FARM IMPLEMENTS 



AND 



FARM MACHINERY, 



AND THE 



f 



Principles of their Construction and Use 

"WITH 

SIMPLE AND PRACTICAL EXPLANATIONS 

OF THE 

H.ATVS OF MOTION -AJSTD FORCE 

AS APPLIED 

ON THE FARM. 

^Vith. 887 Illustrations. 



BY 

JOHN J. THOMAS. 

n 

NEW YORK: 
ORANGE JUDD AND COMPANY, 

245 BROADWAY, 



Entered according to Act of Congress, in the year 1S69, by 

JOHN J. THOMAS, 

In the Clerk's Office of the District Court of the United States for the Southern 
District of New York. 



.^ 



^iK^ 



PREFACE. 



A small treatise, — the basis of the present work, — was 
originally published in the Transactions of the New York 
State Agricultural Society for T850, under the title of 
"Agricultural Dynamics," or the Science of Farm 
Forces. A revised and greatly enlarged edition, adapted 
to general use, was afterwards issued in book form, with 
the name of " Farm Implements." Since the appearance 
of the earlier editions, great and rapid improvements have 
been made in farm machinery of nearly every kind ; and 
the aim of the work in its present form is to supply, so 
far as its limits will admit, the information eagerly sought 
by cultivators in relation to all that has proved of value. 

Another principal object has been to present in a simple 
and intelligible manner, the leading principles of Mechan- 
ical Science, applied directly in the farmer's daily routine, 
— that he may know the reasons of success and failure, 
and not be guided by random guessing. The first portion 
of the book is chiefly devoted to a practical explanation 
of these principles. 

Union Springs, N. Y., 1869. 



CONTENTS. 



PART L— MECHANICS. 
CHAPTER I. 
Introduction. — Value of Farm Machinery — Importance of a 

Knowledge of Mechanical Principles 7-10 

CHAPTER II. 
General Principles of Mechanics. — Inertia, Experiments and 
Examples — Inertia of Moving Bodies, or Momentum — East 
Riding — The Tiger's Leap — Pile Engines— Fly-wheel— Esti- 
mating the Quantity of Momentum — Compound Motion — 
Various Examples — Centrifugal Force 10-22 

CHAPTER III. 

Attraction. — Gravitation — Velocity of Falling Bodies — Resist- 
ance of the Air — Coin and Feather — Galileo's Famous Experi- 
ment — Cohesion — Soils — Strength of Materials — Capillary 
Attraction— The Earth a Desert without it— The Ascent of 
Sap — Centre of Gravity — Experiments — Upsetting Loads — 
Shouldering Bags— Rocking Bodies 22-42 

CHAPTER IV. 

Simple Machines, or Mechanical Powers.— Law of Virtual 
Velocities — The Lever — Many Examples of Levers — Esti- 
mating the Power of Levers — Three-horse Wbiffle-tree — 
Compound Levers — Weighing Machines — Stump Pullers — 
A Wild Theory — Wheel and Axle— Examples — Band and 
Cog-work — The Pulley — Packer's Stone Lifter — The Inclin- 
ed Plane— Crooked Roads — Power of Locomotives — Good 
and Bad Roads — The Wedge — The Screw — Knee-joint Pow- 
er — Lever Washing Machine — Cheese Presses — Rolling Mills 

—Straw Cutters 42-74 

CHAPTER V. 

Application of Mechanical Principles in the Structure of 
Implements and Machines — Various Examples — Calculating 
the Strength of Parts 75-81 

CHAPTER VI. 

Friction. — How to ascertain its Amount — Friction on Roads — 
Resistance of Mud — The Results of the Dynamometer — 
Width of Wheels — Velocity — Size of Wheels on Roads — 
Friction Wheels — Lubricating Substances — Friction neces- 
sary to Existence 81-93 

CHAPTER VII. 

Principles of Draught— Applied to Wagons— To Plows— Comr 
bined Draught of Animals — Whiffle-trees for Three Horses^ 
4 






CONTENTS. V 

Potter's do. — Wier's Single-tree— The Dynamometer— Self- 
registering do. — Waterman's do. — Dynamometer for Rotary 
Motion 93-108 

CHAPTER VIII. 
Application of Labor. — Power of Horses — Of Men — Best Way 

to Apply Strength 108-113 

CHAPTER IX. 
Models op Machines. — Common Blunders— Works of Creation 

Free from Mistakes 113-115 

CHAPTER X. 

Construction and Use op Farm Implements and Machines 
— Implements of Tillage. — Importance of Simplicity — 
Plows — Rude Specimens — Cast-iron and Steel do. — Charac- 
ter of a Good Plow — The Cutting Edge— Mould- board- 
Easy Running Plows — Crested Furrow Slices— Lapping and 
Flat Furrows— How to Plow Well— Fast and Slow Plowing 
— The Double Michigan— The Subsoil Plow— The Paring 
Plow— Gang Plow— Ditching Plow— Mole Plow— Coulters 
— Weed Hook and Chain— Pulverizers— Harrows— Ged- 
des' Harrows — Scotch do. — Morgan Harrow — Norwegian 
do.— Shares' do.— Cultivators— Holbrook's— Alden's— Gar- 
rett's Horse-hoe— Two-horse Cultivators— Sulky do.— Coin- 
stock's Spader— Clod Crushers— Roller 115-152 

CHAPTER XI. 
Sowing Machines— Wheat Drills— Bickford and Huffman's do. — 
Seymour's Broadcast Sower— Corn Plauters — True's Po- 
tato Planter— Hand Drills 152-157 

CHAPTER XII. 
Machines for Haying and Harvesting. — Mowing and Reap- 
ing Machines — Cutter-bar — Combined Machines — Self 
Rakers— Johnson's do. — Marsh's and Kirby's do. — Dropper 
— Binders — Marsh's Harvester — Durability and Selection of 
Machines— Hay Tedders— Bullard's do. — American do. — 
Horse Rakes— Revolving do.— Sulky Revolvers— Warner's 
do. — Spring Tooth Rakes — Hollingsworth's do. — Hay 
Sweep— Horse Forks— Gladding's do.— Palmer's, Myers' 
Beardsley's, Raymond's — Harpoon Forks — Hay Carriers — 
Hicks' do.— Building Stacks— Palmer's Hay Stacker— Ray- 
mond's Hay Stacker— Dcderick's Hay Press— Beater do. — 
Hay Loaders 158-186 

CHAPTER XIII. 
Thrashing, Grinding, and Preparing Products. — Value of 
Thrashing Machines — Endless Chain Power — How to 
Measure Power of— Churning by Tread Power— Pitt's Ele- 



VI CONTENTS. 

vator — Corn Shellers — Burralls', Richards' — Root Washer 
— Root Slicers — Farm Mills, Allen's, Forsman's — Emery 
Cotton Gin 186-197 

PART II— MACHINERY IN CONNECTION WITH WATER. 

CHAPTER I. 

Hydrostatics. — Upward Pressure — Measuring Pressure — Cal- 
culating Strength of Tubes, etc. — Artesian Wells — Determ- 
ining Pressure in Vessels — A Puzzle Explained — Hydro- 
static Bellows— Press — Specific Gravities — Table of do. — 
Weigbt and Bulk of a Ton of Different Substances 198-210 

CHAPTER II. 
Hydraulics. — Velocity of Water — Discharge of Water through 
Pipes — Velocity in Ditches — Leveling Ditches — Archime- 
dean Screw-pumps — For Cisterns — Non-freezing do. — For 
Deep Wells — Drive Pumps — Chain Pumps — Rotary do. — 
Suction and Forcing Pump — Turbine Water Wheels — The 
Water Ram — Water Engines for Gardens — Flash Wheel — 
Nature of Waves — Size of do. — Preventing Inroads by do. 
— Cisterns — To Determine Contents of 211-238 

PART III.— MACHINERY IN CONNECTION WITH AIR. 

CHAPTER I. 
Pressure of Air. — Weigbt of the Atmosphere — Hand Fastened 

by Air — Barometer — Measuring Heights — Syphon 239-245 

CHAPTER II. 
Motion of Air. — Wiuds — Wind-mills, how Used — Brown's do. 
— Causes of Wind — Chimney Currents — Construction of 
Chimneys — To Cure Smoky do. — Chimney Caps — Ventila- 
tion 245-259 

PART IV.— HEAT. 
CHAPTER I. 

Conducting Power — Expansion, Great Force of— Experiments 
with — Steam Engine — do., for Farms — Steam Plows — 

Latent Heat— Green and Dry Wood 260-276 

CHAPTER II. 

Radiation. — Several Examples in Domestic Economy — Dew and 

Frost— Frost in Valleys— Sites for Fruit Orchards 276-280 

APPENDIX. 

Apparatus for Experiments 281-283 

Discharge of Water through Pipes 284 

Velocity of Water in Pipes 284 

Rule for Discharge of Water 285-286 

Velocity of Water in Tile Drains 286 

Glossary 287-296 



FARM IMPLEMENTS 



AND 



FARM MACHINERY. 



PART I. 

MECHANICS. 



CHAPTER I. 

INTRODUCTION. 

No farm can be well furnished without a large number 
of machines and implements. Scarcely any labor is per- 
formed without their assistance, from the simple opera- 
tions of hoeing and spading, to the more complex work 
of turning the sod and driving the thrashing-machine. 
The more perfect this machinery, and the better fitted to 
its work, the greater will be the gain derived by the farm- 
er from its use. It becomes, therefore, a matter of vital 
importance to be able to construct the best, or to select 
the best already constructed, and to apply the forces re- 
quired for the use of such machines to the greatest possi- 
ble advantage. 



8 MECHANICS. 



Nothing shows the advancement of modern agriculture 
in a more striking light than the rapid improvement in 
farm implements. It has enabled the farmer within the 
last fifty years to effect several times the work with an 
equal force of horses and men. Plows turn up the soil 
deeper, more evenly and perfectly, and with greater ease 
of draught; hoes and spades have become lighter and 
more efficient ; grain, instead of being beaten out by the 
slow and laborious work of the flail, is now showered in 
torrents from the thrashing-machine ; horse-rakes accom- 
plish singly the work of many men using the old hand- 
rake ; horse-forks convey hay to the barn or stack with 
ease and rapidity ; twelve acres of ripe grain are neatly 
cut in one day with a two-horse reaper ; grain drills and 
planting machines, avoiding the tiresome drudgery of hand 
labor, distribute the seed for the future crop with even- 
ness and precision. 

The owner of a seventy-thousand-acre farm in Illinois 
carries on nearly all his work by labor-saving machinery. 
He drives posts by horse-power ; breaks his ground with 
Comstock's rotary spader ; mows, rakes, loads, unloads, 
and stacks his hay by horse-power ; cultivates his corn 
with two-horse, seated or sulky cultivators ; ditches low 
ground, sows and plants by machinery ; so that his labor- 
ers ride in the performance of their tasks without exhaust- 
ing their strength with needless walking over extended 
fields. 

The great value of improved farm machinery to the 
country at large has been lately proved by the introduc- 
tion of the reaper. Careful estimate determined that the 
number of reaping machines introduced throughout the 
country up to the beginning of the great rebellion, per- 
formed an amount of labor while working in harvest 
nearly equal to a million of men with hand implements. 
The reaper thus filled the void caused by the demand on 
workingmen for the army. An earlier occurrence of that 



VALUE OF FARM MACHINERY. 9 

war must therefore have resulted in the general ruin of 
the grain interest, and prevented the annual shipment of 
the millions during that gigantic contest, which so greatly 
surprised the commercial savans of Europe. 

The implements and machines which every farmer must 
have who does his work well are numerous and often 
costly. A farm of one hundred acres requires the aid of 
nearly all the following; two or more good plows, a 
shovel-plow, a small plow, a subsoiler, a single and two- 
horse cultivator, a seed-planter, a grain-drill, a roller, a 
harrow, a fanning-mill, a straw-cutter, a root-slicer, a farm 
wagon with hay-rack, an ox-cart, a horse-cart, wheel-bar- 
row, sled, shovels, spades, hoes, hay-forks and manure- 
forks, hand-rakes and horse-rakes, scythes and grain- 
cradle, grain-shovel, maul and wedges, pick, axes, wood- 
saw, hay-knife, apple-ladders, and many other smaller con- 
veniences. The capital for furnishing the farms in the 
Union has been computed to amount to more than five 
hundred millions of dollars, and as much more is estimat- 
ed to be yearly paid for the labor of men and horses 
throughout the country at large. To increase the effect- 
ive force of labor only one-fifth would, therefore, add an- 
nually one hundred millions in the aggregate to the profits 
of farming. 

A knowledge of the science of mechanics is not so well 
understood among all classes of people as it should be. A 
loss often occurs from the want of a correct knowledge 
of mechanical principles. The strength of laborers is 
badly applied by the use of unsuitable tools, and that of 
teams is partly lost by being ill adjusted to the best line 
of draught. We may perhaps see but few instances of 
so great a blunder as the ignorant teamster committed 
who fastened his smaller horse to the shorter end of the 
whiffle-tree, to balance the large horse at the longer end ; 
yet instances are not uncommon where operations are per- 
formed to almost as great a disadvantage, and which, to 
1* 



10 ■ MECHANICS. 

a person well versed in the science of mechanics, would 
appear nearly as absurd. 

It is well worth while to look at the achievements made 
through a knowledge of mechanical principles. Compare 
the condition of barbarous and savage tribes with that of 
modern civilized nations. The former, scattered in com- 
fortless hovels, subsist by precarious hunting, or on scanty 
crops raised on patches of ground by means of the rudest 
tools. The latter are blessed with smooth, cultivated fields, 
green meadows, and golden harvests. Commerce with 
its hum of business, extending through populous cities, 
and along a hundred far-stretching lines of rail-ways, scat- 
ters comforts and luxuries to millions of homes ; while 
ships for foreign commerce thread every channel and 
whiten every sea. The contrast exhibits the difference 
between ignorance on the one hand, and the successful 
application of scientific principles on the other. It is our 
present object to point out to the farmer the advantages 
which would result from a wide extension, through all 
classes, of this knowledge, that the opportunities may be 
continually increased for general improvement. 



CHAPTER II. 

GENERAL PRINCIPLES OF MECHANICS. 

Having briefly pointed out some of the advantages to 
the farmer of understanding the principles of the ma- 
chines he constantly uses, we now proceed to an examina- 
tion of these principles. It will be most convenient to 
begin with the simpler truths of the science, proceeding, 
as we advance, to their application in the construction of 
machines. 



INERTIA. — EXPERIMENTS AND EXAMPLES. 



11 



rNERTIA. 



An important quality of all material bodies is inertia. 
This term expresses their passive state — that is, that no 
body (not having life), when at rest, can move itself, nor, 
when in motion, can stop itself. A stone has not power 
to commence rolling of its own accord ; a carriage can not 
travel on the road without being drawn ; a train of cars 
never commences gliding upon the rails without the power 
of the locomotive. 

On the contrary, a body, when once set in motion, will 
continue in motion perpetually, unless stopped by some- 
thing else. A cannon ball rolled upon the ground moves 
on until its force is gradually overcome by the resistance 
of the rough earth. If a polished metallic globe were driven 
swiftly on a level and polished metallic plane, it would 
Fig. i. continue in motion a long time and 

travel to a great distance ; but still 
the extremely minute roughness of 
the surfaces, with the resistance of the 
air, would continually diminish its 
speed until finally stopped. A wheel 
made to spin on its axis revolves un- 
til the friction at the axis and the 
impeding force of the air bring it to 
rest. But if the air is first removed, 
Fans revolving in a vacuum. Dv means of an air-pump, the mo- 
tion will continue much longer. Under a glass receiver, 
thus exhausted, a top has been made to spin for hours, 
and a pendulum to vibrate for a day. The resistance of 
the air may be easily perceived by first striking the edge 
and then the broad side of a large piece of pasteboard 
against the air of a room. It is further shown by means 
of an interesting experiment with the air-pump. Two 
fan-wheels, made of sheet tin, one, a, striking the air 
with its edges, and the other, b, with its broad faces (fig. 





12 MECHANICS. 

1), are set in motion alike; b is soon brought to rest, 
while a continues revolving a long time. If now they are 
placed under the receiver of an air-pump, the air exhaust- 
ed, and motion given to them alike by the rack-work c?, 
they will both continue in motion during the same period. 
There is no machinery made by man free from the 
checking influence of friction and the air; and for this 
reason, no artificial means have ever devised a perpetual 
motion by mechanical force. But we are not without a 
proof that motion will continue without ceasing when 
nothing operates against it. The revolutions of the planets 
in their orbits furnish a sublime instance ; where removed 
from all obstructions, these vast globes wheel around in 
their immense orbits, through successive centuries, and 
with unerring regularity, preserving undiminished the 
mighty force given them when first launched into the re- 
gions of space. 

To set any body in motion, a force is requisite, and the 
heavier the body, the greater must be the force. A small 
stone is more easily thrown by the hand than a cannon 
ball ; speed is more readily given to a skiff than to a large 

and heavy vessel ; but the same force 
which sets a body in motion is re- 
>C quired to stop it. Thus a wheel or a 
grindstone, made to revolve rapidly, 
would need as great an effort of the 
arm to stop it suddenly as to give it 
u ' sudden motion. An unusual exertion 

Inertia Apparatus. 

of the team is necessary in starting a 
loaded wagon; but when once on its way, it would 
require the same effort of the horses to stop it as to back 
it when at rest. 

The force of inertia is finely exhibited by means of a 
little instrument called the inertia apparatus (fig. 2). A 
marble or small ball is placed on a card, c, resting on a 
concave stand. A spring snap is then made to strike the 




INERTIA. — EXPERIMENTS AND EXAMPLES. 



13 



Fig. 3. 





card, throwing it to a distance, but leaving the ball upon 
the hollow end of the stand. The same experiment may- 
be easily performed by placing a very small apple or other 
solid on a card, the whole resting on a common sand-box, 
or even the hollow of the hand. A sud- 
den snap with the finger will throw the 
card away, while the apple will drop into^ 
the cavity. The following experiment is 
still more striking : Procure a thread 
just strong enough to bear three pounds, 
and hang upon it a weight of two pounds 
and a half. Another half pound would 
break it. Now tie another thread, strong 
enough to bear one pound, to the lower 
hook of the weight. If the lower thread 
be pulled gradually, the upper thread 
will of course break ; but if it be pulled 
with a jerk, the lower thread will break. 
If the jerk be very sudden, the lower string will break, 
even it be considerably stronger than the upper, the in- 
ertia of the weight requiring a great force to overcome it 
suddenly. The threads used in this experiment may be 
easily had. of any desired strength by taking the finest 
sewing cotton, and doubling to any desired extent. 

This experiment shows the reason why a horse, when 
he suddenly starts with a loaded wagon, is in danger of 
breaking the harness ; and why a heavier weight may be 
lifted with a windlass or pulley having a weak rope, if the 
strain is gradual and not sudden. For the same reason, 
glass vessels full of water are sometimes broken when 
hastily lifted by the handle. When a bullet is fired through 
a pane of glass, the inertia retains the surrounding glass 
in its place during the moment the ball is passing, and a 
round hole only is made; while a body moving more 
slowly, and pressing the glass for a longer space of time, 
fractures the whole pane. 



14 MECHANICS. 

INERTIA OF MOVING BODIES, OR MOMENTUM. 

Momentum is the inertia of a moving body. When a 
force is applied to a heavy body, its motion is at first slow ; 
but the little momentum it thus acquires, added to the ap- 
plied force, increases the velocity. This increase of velocity 
is of course attended with increased momentum, which 
again, added to the acting force, still further quickens the 
speed. For this reason, when a steam-boat leaves the pier, 
and its paddle-wheels commence tearing through the wa- 
ter, the motion, at first slow, is constantly accelerated un- 
til the increasing resistance of the water becomes equal 
to the strength of the engine and the momentum.* Were 
it not for the momentum of moving bodies (inertia exist- 
ing), no speed ever could be given to any heavy body, as 
a carriage, boat, or train of cars. 

The chief danger in fast riding, or fast traveling of any 
kind, is from the momentum given to the traveler. If a 
rail-way passenger should step from a car when in full mo- 
tion, he would strike the earth with the same velocity as 
that of the train ; or if the train at thirty miles an hour 
should be instantly stopped, the passengers would be 
pitched forward with a swiftness equal to thirty miles an 
hour. When a horse suddenly stops, the momentum of 
the rider tends to throw him over the horse's head. When 
a wagon strikes an obstruction, the driver falls forward. 
A case in court was once decided against the plaintiff, who 
claimed that the defendant had driven against his wa^on 
with such force as to throw the plaintiff to a great distance; 
but the fact was shown that by such momentum he him- 
self must have been driving furiously, and not the defend- 
ant, and he lost his suit. 



* In ordinary practice, this is not strictly correct, as friction will make 
some difference. This influence will be more particularly considered on 
a subsequent page. Its omission here does not at all alter the principle 
under consideration. 



MOMENTUM. EXAMPLES. 



15 



An Eastern traveler once succeeded in saving his life by 
a ready knowledge of this principle. He was closely pur- 
sued by a tiger, and when near a precipice, watching his 

opportunity, he threw his coat and 
hat on a bush, and jumped one 
side, when the animal, leaping swift- 
ly on the concealed bush, was car- 
ried by momentum over the prec- 
ipice. 

As a large or heavy body pos- 
sesses greater momentum than a 
small or light one, so any body 
moving with great speed possesses 
more than one moving slowly ; for 
instance, the momentum of a rifle 
ball is so great as to carry it through 
a thick plank, while, if thrown slow- 
ly, it would scarcely indent it. 

This property of bodies is applied 
with great advantage to many 
practical purposes. The momentum 
of the hammer drives the nail into 
the wood; for the mere pressure 
of its weight would not do it, if it 
were a hundred times as heavy. 
Wedges are driven by employing 
the same kind of power. 

On a larger scale, the pile-engine 

operates in a similar manner. The 

ram or weight, h (fig. 4), is slowly 

lifted by means of a pulley and 

wheel-work, worked by the handles or cranks, b b, until 

the arms of the tongs which hold the ram are compressed 

in the cheeks, % i, when it suddenly falls with prodigious 

force on the pile or post to be driven. , In this Avay long 

posts of great size are forced into the mud of swamps and 




Pile Engine. 



10 



MECHANICS. 



Fie. 5. 



river bottoms, "where other means would fail. When a 
steam-engine is used for lifting the ram, the work is more 
rapidly performed. 

An interesting example of the use and efficiency of 
momentum is furnished by the water-ram, a machine for 
raising water, described on a subsequent page. 

The fly-wheel, a large and heavy wheel used to regulate 
the motion of machinery, derives its value from the power 
of inertia, or momentum, which prevents the machine 
from stopping suddenly when it meets with any unusual 
obstruction. In the common thrashing-machine, it has 
been found that a heavy cylinder, by acting as a fly-wheel, 
renders the motion steadier, and less liable to become im- 
peded by large sheaves of grain. An ignorance of this 
principle has sometimes proved a serious inconvenience. 
A farmer, having occasion to raise a large quantity of 
water, erected a horse-pump ; but at every stroke of the 

pump the animal was sud- 
denly thrown loosely for- 
ward, and again jerked back- 
ward, as the piston fell light- 
ly and rose heavily. A fly- 
wheel attached to the ma- 
chinery would have prevent- 
ed this unpleasant jerking, 
and have enabled the horse, 
straw-cutter with fly-xckcci. ^ conge quence, to accom- 

plish more work. In the pile-driving engine, where a great 
weight is suddenly thrown loose from a height, the horses 
would be pitched forward when suddenly relieved of this 
load but for the regulation of a fly-wheel, the motion of 
which is not quickly changed, neither from fast to slow nor 
from slow to fast. 

Where there is a rapid succession of forces required in 
practice, the fly-wheel is usually of great advantage. 
Hence its use in all revolving straw-cutters, where the 




INERTIA. THE FLY-WHEEL. 



17 



knives make quickly-repeated strokes (fig. 5). More re- 
cently it has been applied to the dasher-churn (fig. 6), 
where the rapid upright strokes are so well known to be 
very fatiguing for the amount of force applied. 

By thus regulating motion, the fly-wheel frequently 
enables an irregular force to accomplish work which other- 
wise it could not perform. Thus a man may exert a force 
equal to raising a hundred pounds, Fig. 6. 

yet, when he turns a crank, there 
is one part of the revolution where 
he works to great disadvantage, 
and where his utmost force will 
not balance forty pounds. Hence, 
if the work is heavy, he may not 
be able to turn the crank, nor to 
do any work at all. If, however, 
a fly-wheel be applied, by gather- 
ing force at the most favorable 
part of the turning, it carries the 
crank through the other part. 

An error is sometimes commit- 
ted by supposing the fly-wheel actually creates power, for 
as much force is required to give it momentum as it 
afterward imparts to the machine ; it consequently only 
accumulates and regulates power. 

On rough roads, the force of inertia causes a severe 
strain to a loaded wagon when it strikes a stone. The 
horses are chafed, the wagon and harness endangered, and 
the load jarred from its place. This inconvenience is 
avoided in part by placing the box upon springs, which, by 
yielding to the blow, gradually lessen the effects of the 
shock. For carts and slowly moving lumber-wagons 
springs are useful, but more so as the velocity and 
momentum increase. Even on so smooth a surface as a 
rail-road, it was found by experiments made some years 
ago, that when the machinery of a locomotive was placed 




Churn with a fly-wheel, for equal* 
izinff the motion. 



18 MECHANICS. 

upon springs, it would endure the wear and tear of use 
four times as long as without them. 

For this reason, a ton of stone, brick, or of sand, is harder 
for a team than a ton of wool or hay, which possesses con- 
siderable elasticity. 

ESTIMATING THE QUANTITY OE MOMENTUM. 

The quantity of momentum is estimated by the velocity 
and weight of the body taken together. Thus a ball of 
two pounds weight moves with twice the force of a one- 
pound ball, the speed being equal ; a ten-pound ball with 
ten times the force, and so on. A body moving at the 
rate of two feet per second possesses twice the momentum 
of another of equal size with a velocity of only one foot 
per second. A musket ball, weighing one ounce, flying 
with fifty times the speed of a cannon ball, weighing fifty 
ounces, would strike any object with equal force ; or, if 
they should meet each other from opposite directions, the 
momentum of both would be mutually destroyed, and 
they would drop to the earth. 

Where the mass is very great, even if the motion is 
slow, the momentum is enormous. A large ship floating 
near a pier wall may approach it with so small a velocity 
as to be scarcely perceptible, and yet the force would be 
enough to crush a small boat. When great weight and 
speed are combined, as in a rail-way locomotive, the force 
is almost irresistible. This circumstance often insures the 
safety of the passengers ; for as nothing is capable of 
instantly overcoming so powerful a momentum, when 
accidents occur the speed is more gradually slackened, 
and the passengers are not pitched suddenly forward. A 
light wagon, rapidly driven, possessing but little compara- 
tive force, is more suddenly arrested, and the danger is 
greater. 

When two bodies meet from opposite directions, each 



COMPOUND MOTION. 19 

sustains a shock equal to the united forces of both. Two 
men accidentally coming in contact, even if walking 
moderately, receive each a severe blow ; that is, if each 
were walking three miles an hour, the shock would be the 
same as if one at rest were struck by the other with a 
velocity of six miles an hour. This principle accounts for 
the destructive effects of two ships running foul of each 
other at sea, or of the collision of two opposite trains on 
a rail-road. 

The preceding principles show that a sledge, maul, or 
axe will always strike more effective blows when made 
heavier, if not rendered unwieldy. 



COMPOUND MOTION. 

It often happens that two or more forces act on the 
same body at the same time. If they all act in the same 
direction, the effect will be equal to the sum of the forces 
taken together ; but if they act in opposite directions, the 
forces will tend to destroy each other. If two equal 
forces act in contrary directions, they will be completely 
neutralized, and no motion will be produced. Thus, as 
an example of these forces — a bird flying at the rate of 
forty miles an hour, with a wind blowing forty miles an 
hour, will be driven onward by these two combined forces 
eighty miles an hour ; but if it undertake to fly against 
such a wind, it will not advance at all, but remain station- 
ary. A similar result will take place if a steam-boat, 
having a speed of ten miles an hour, should first run 
down a river with a current of equal volocity, and then 
upward against the current ; in the first case it would 
move twenty miles an hour, and in the latter it would not 
move at all. 

Where forces act neither in the same nor in opposite 
directions, but obliquely, the result is found in the follow- 




20 MECHANICS. 

ing manner: If a ball, placed at the point a (fig. 7), be 
struck by two different forces at the same moment, in the 
Fi(r 7 direction shown by the two ar- 

rows, and if one force be just suf- 
ficient to carry it from a to c, 
and the other to carry it from a 
to b, then it will move inter- 
mediate between the two, in the 
direction of the diagonal of the 
parallelogram a d, and to a dis- 
tance just equal to the length of this diagonal or cross- 
diameter. 

"When the forces act very nearly together, the parallelo- 
gram of the forces will be very narrow aud quite long, 
with a long diagonal Fig. 8. 

(fig. 8) ; but if they act 
on nearly opposite sides 
of the ball, they will 

very nearly neutralize each other, and the diagonal or re- 
sult will be very short, showing that the motion given to 
the ball will be very small (fig. 9). 

These examples show the importance of having teams 
attached to a plow or to a wagon very nearly in a straight 
line with the draught, or else a part of the force will be 
Fig. 9. lost ; and also the impor- 

-^fi tance, when several animals 

are drawing together, of 
their working as nearly as 
possible in the same straight line. For, the more such 
forces deviate from a right line, the more they will tend 
to destroy or neutralize each other. 

A familiar example of the result of two oblique forces 
is furnished when a boat is rowed across a river. If the 
river has no current, the boat will pass directly from bank 
to bank perpendicularly ; but if there is a current, its track 
will form a diagonal, and it will strike the opposite bank 



CENTRIFUGAL FORCE. 



21 



lower down, according to the rapidity of the stream and 
the slowness of the boat. 

Another instance is afforded when a ferry-boat is 
anchored, by means of a long rope, to a point some dis- 
tance above (fig. 10) ; the boat, being turned obliquely, 
will pass from one bank to the other by the force of the 
current. Here the water tends to carry the boat down- 
Fig. 10. ward, while the 

force of the rope 
acts upward ; the 
boat passes be- 
tween the two 
from bank to 
bank. The ascent of a kite is precisely similar, the wind 
and the string being counteracting forces. When a vessel 
sails under a side wind, the resistance of the keel against 
the water, and the force of the wind against the sail, act 
in different directions, and produce a motion of the vessel 
between them. 

CENTRIFUGAL FORCE. 




All bodies, when in motion, have a tendency to move 
forward in a straight line. A stone thrown into the air is 
gradually bent from this straight course into a curve by 
the attraction of the earth. When a ball is shot from a 
gun, the force being greater, it flies in a longer and 
straighter curve. A familiar example also occurs, while 
driving a wagon rapidly, in attempting to turn suddenly 
to the right or left ; the tendency of the load to move 
straight on will sometimes cause its overthrow. An 
observance of this principle would prevent the error which 
some commit by making sharp turns or angles in ditches 
and water-courses ; the onward tendency of the water 
drives it against the bank, checks its course, and wears 
away the earth. By giving the ditch a curve, the water 



22 MECHANICS. 

is but slightly impeded, and a much larger quantity will 
escape through a channel of any given size. 

When a grindstone is turned rapidly, the water upon 
its surface is thrown off by this tendency to move in 
straight lines. In the same way, a weight fastened to a 
cord, whirled by the hand, will keep the cord stretched 
during the revolution. A cup of water, attached to a 
cord, may be swung over the head without spilling, the 
water being held by centrifugal force. The same principle 
causes a stone, when it leaves a sling, to fly off in a line. 
This tendency to fly off from a revolving centre is called 
centrifugal force — the word centrifugal meaning flying 
from the centre. Large grindstones, driven with great 
velocity by machinery, are sometimes sj>lit asunder by 
centrifugal force. 

The most sublime examples of this force occur in the 
motion of the earth and planets, which will be more fully 
explained in a future page. 



CHAPTER in. 

ATTRACTION. 
GRAVITATION. 

The earth, as is well known, is a mass of matter in the 
form of a globe, the diameter being upward of 7900 miles. 
From its enormous size and the small portion seen from 
one point, the surface appears flat, except where broken 
into mountains and valleys. 

The tendency which all bodies possess of falling toward 
the earth is owing to the attractive force which this great 
mass of matter exerts upon them. This kind of attrac- 



GRAVITATION". VELOCITY OF FALLING BODIES. 



23 



tion is called gravitation. The force with which a body- 
is thus drawn is the iceight of that body. 

When a stone is dropped from the hand, its velocity is 
at first slow, but continues to increase till it strikes the 
earth ; hence, the further it falls the harder it will strike. 
This accelerated motion is precisely similar to that of a 
steam-boat when it first leaves the wharf; the force of 
gravity may be compared to the driving power of the 
engine, and the quickened velocity of the falling stone 
to the increased headway of the boat. 

All bodies, whether large or small, fall equally fast, un- 
less they are so light as to be borne up in part by the 
resistance of the air. In the first second of time they fall 
16 feet; in the second, 3 times 16, or 48 feet ; in the third 
second, 5 times 16, or 80 feet, and so on. Or, if the whole 
distance fallen be taken together, they fall 16 feet in one 
second, 4 times 16 in two seconds, 9 times 16 in three 
seconds, and so forth. In other words, the whole distance 
is equal to the square of the time. This is plainly ex- 
hibited iu the following table : 



Seconds, from beginning 
to fall. 


1 


2 


3 


4 


5 


6 


Whole height fallen in 
feet. 


16 


4X16 
or64. 


9X16 
or 144. 


16X16 
or 256. 

7X16 
or 112. 


25X16 
or 400. 


36X16 
or 576. 


Space fallen in each sec- 
ond in feet. 


16 


3X16 

or 48. 


5X16 
or 80. 


9X16 
or 144. 


11X16 
or 176. 



A stone or other body will fall 1 foot in a fourth of a 
second, 3 feet the next fourth, 5 feet the third fourth, and 
7 feet the last fourth ; which is the same as 4 feet in half 
a second, 9 feet in three-fourths of a second, and 16 feet 
for the whole second. 

The depth of an empty well, or the height of a preci- 
pice, may be nearly ascertained by observing the time 
required for the fall of a stone to the bottom. The time 
may be measured by a stop-watch, or, in its absence, a 
pendulum may be made by fastening a pebble to a cord, 
which will swine: from the hand in regular vibrations of 



24 MECHANICS. 

an exact second each if the cord be 39J inches long, or of 
half a second each if it be about 9f inches long. 

The velocity increases simply as the time, that is, the 
speed in falling is twice as great in two seconds as in one ; 
three times as great in three seconds ; four times as great 
in four seconds, and so forth. A stone will fall four times 
as far in two as in one second, while its velocity will be 
doubled ; nine times as far in three seconds, while its 
velocity will be tripled, etc. 

If a stone is thrown upward, its motion continues 
gradually to decrease, at the same rate as it increases in 
falling ; hence the same time is required to reach its 
highest point, as to fall from that point back to the earth. 
Therefore the velocity with which it is first projected up- 
ward is equal to the velocity which it attains at the 
moment of striking the ground. There is an exception, 
however, to this general rule. In a vacuum it would be 
perfectly correct, but in ordinary practice the resistance 
of the air tends to diminish the velocity while ascending, 
and still further to retard it while descending. For this 
reason, it will fall with less speed than it first arose. For 
heavy bodies and small distances, this exception would be 
imperceptible ; but with small bodies falling from great 
heights, the difference will be considerable. 

The velocity of a stone after falling one second, or six- 
teen feet, is at the rate of thirty-two feet per second; 
hence, if thrown upward at that rate, it will rise just six- 
teen feet high. After falling three seconds, the rate is 
ninety-six feet ; and hence, if projected upward at ninety- 
six feet per second, it will rise nine times sixteen feet, or 
one hundred and forty-four feet high. And so of other 
heights. 

Were it not for the resistance of the air, a feather would 
fall as swiftly as a leaden ball. This is conclusively shown 
by an interesting experiment. A tall glass jar (fig. 11), 
open at the bottom, is covered with a brass cap, fitting it 



TELOCITY OF FALLING BODIES. 



25 



Fig. 11. 



air-tight. Through this cap passes an air-tight wire, which, 
by turning, opens a small pair of pincers. Within these 
are placed a feather and a half dollar, and the air is then 
thoroughly drawn from the receiver by means of an air- 
pump. The wire is turned, and the feather and coin both 
drop at once, and strike the bottom at the same moment. 

There are many examples showing the accelerated 
motion and increased force of falling 
bodies. When a large stone rolls down 
a mountain, it first moves slowly, but 
afterwards bounds with rapidity, sweep- 
ing before it all smaller obstacles. Hail- 
stones, although small, acquire such veloc- 
ity as to break windows ; and but for 
the resistance of the air, they would be 
much more destructive. The blow of a 
sledge-hammer is more severe as it is lifted 
to a greater height. Newton was first 
led to the examination of the laws of 
gravity by observing, when sitting under 
an apple-tree, that the fruit struck his 
hand with greatest severity when it fell 
from the top of the tree. 

It is not an unusual error to suppose 
that a large body will fall more rapidly 
than a small one. Some can scarcely be- 
lieve that a fifty-Six pound Weight Will Feather and coin falling 

not drop with a greater velocity than a ^e m a vacuum. 
small nail, not remembering that a proportionately 
greater force is required to overcome the inertia and 
set the larger body in motion. This error existed for 
many centuries, from the time of Aristotle until Galileo 
first questioned its correctness. The celebrated ex- 
periment which established the truth on this subject, 
and led to the discovery of the laws of falling bodies 
just explained, and which formed an era in modern 




26 MECHANICS. 

philosophy, was performed from the top of the leaning 
tower of Pisa. Galileo was a philosophical teacher, and, 
being a man who thought for himself, soon discovered, by 
reasoning, the errors that had been received without a 
doubt for more than twenty centuries. All the learning 
of the age and the wisdom of the universities were against 
him, and in favor of this time-honored error, the truth of 
which no one had ever thought of submitting to experi- 
ment. The hour of trial arrived, when he, an obscure 
young man, stood nearly alone on one side, while the 
multitude, with all the power and confessed knowledge 
of the age, were on the other. 

The balls to be employed were carefully weighed and 
scrutinized to detect deception, and the parties were satis- 
fied. The one ball was exactly twice the weight of the 
other. The followers of Aristotle maintained that when 
the balls were dropped from the top of the tower, the 
heavy one would reach the ground in exactly half the 
time employed by the lighter ball. Galileo asserted that 
the weights of the balls would not affect their velocities, 
and that the times of descent would be equal. The balls 
were conveyed to the summit of the lofty tower — the 
crowd assembled round the base — the signal was given — 
the balls were dropped at the same instant, and swiftly 
descending, at the same moment struck the earth. Again 
and again the experiment was repeated with uniform 
results. Galileo's triumph w r as complete — not a shadow 
of doubt remained; but, instead of receiving the con- 
gratulations of honest conviction, private interest, the loss 
of place, and the mortification of confessing false teach- 
ing, proved too strong for the candor of his adversaries. 
They clung to their former opinions with the tenacity of 
despair, and he was driven from Pisa.* 



* Mitchell's Lectures. 



COHESION. — EXAMPLES. 27 



COHESION - . 




The attraction of gravitation, as we have just seen, takes 
place between bodies at a greater or less distance from 
each other. There is another kind of attraction, acting 
only when the parts of substances are in actual contact / 
this is called cohesion. It is this which holds the parts of 
a body together and prevents it from falling to pieces. It 
may be shown by taking two pieces of lead, and, after 
having made upon them two smoothly-shaven surfaces 
with a knife, pressing them firmly together with a twist- 
ing motion (fig. 14). The asperities of the surfaces are 
thus pushed down, and the Fig- 1*. 

particles are brought into 
close contact, so that cohc- W§ 

Sion immediately takes place Cohesive attracttoiiTn'two lead balls'. 

between them, and some force will be required to draw 
them asunder.* Two pieces of melted wax adhere to- 
gether in the same way. Melted pitch or other similar 
substance, smeared thinly over the polished surfaces of 
metal or glass, also causes cohesion to take place between 
them. Smooth iron plates, two inches in diameter, have 
been made to stick together so firmly with hot grease as 
to require, when cold, a weight of half a ton to draw 
them apart. Plates of brass of the same size, cemented 
by means of pitch, required 1400 pounds. On this prin- 
ciple depends the efficacy of those substances which are 
used for cementing broken vessels. 

The most perfect artificial polish which can be given to 
hard metals is still so rough as to prevent the faces from 



*.That this is not atmospheric pressure, like that which holds two 
panes of wet glass together, is shown by the fact that it requires nearly 
as great a force to separate them when the}' are placed under the exhaust- 
ed receiver of an air-pump. Besides this, atmospheric pressure is much 
weaker than this force, with so small a surface. 



28 MECHANICS. 

coming into close contact; hence they must be either 
melted, or softened like iron when it is welded. 

The different degrees of cohesion which take place 
between the particles of various soils, to reunite them 
after they have been crumbled asunder, occasion the main 
difference between light and heavy soils. When a light 
soil becomes soaked with water \ the particles adhere in a 
very slight degree ; and hence, when it becomes dry again, 
it is easily worked mellow. But if it be of a clayey 
nature, too much moisture softens it like melted wax: 
the particles are thus brought into close contact, and 
strong adhesion takes place ; hence the hardness and diffi- 
culty of working such soils when again dried. This ad- 
hesion is lessened by applying sand, chip-dirt, straw, yard- 
manure, or by burning the earth, but more especially by 
thorough draining, which, preventing the clay from be- 
coming so moist and soft, lessens the adhesion of its 
parts. 

Different substances are hard, soft, brittle, or elastic, 
according to the different degrees or modes of action in 
the attraction of cohesion. 



STRENGTH OF MATERIALS. 

It is a matter of great utility in the construction of 
machinery to determine the different degrees of cohesion 
possessed by different substances ; or, in other words, to 
ascertain their strength. This is done by forming them 
into rods of equal size, and applying weights to their 
lower extremities sufficient to break them, by drawing 
them asunder. The amount of weight shows their rela- 
tive degrees of strength. The following table gives the 
weights required to break the different substances, each 
being formed into q rod one quarter of an inch square : 



STEENGTH OF MATEEIAES. 29 

Woods. 

Ash, toughest 1000 lbs. 

Beech 718 « 

Box 1250 " 

Cedar .' 712 " 

Chestnut 656 " 

Elm 837 " 

Locust 1380 " 

Maple 056 " 

Oak, white 718 " 

Pine, white 550 

« pitch 750 " 

Poplar 437 « 

Walnut 487 " 



Metals. 

Steel, best 0370 lbs. 

« soft 7500 « 

Iron, wire 0440 

" best bar 4690 " 

" common bar. . ., 3750 

" inferior bar 1880 " 

it cas t 1150 to 3100 " 

Copper, wire 3S00 

- cast 2030 » 

Brass 2800 " 

Platina wire ooUU 

Silver, cast 2500 

Gold, cast ' !250 " 

Tin 31° " 

Zinc, cast 10° " 

« sheet --1000 « 

Lead, cast 55 

« milled 207 « 

From these tables we may ascertain the strength of 
chains, rods, etc., when made of different metals, and of 
timbers, bars, levers, swing-trees, and farm implements, 
when made of woods. Wood which will bear a very 
heavy weight for a minute or two, will break with two- 
thirds of the weight when left upon it for a long time. 
This explains the reason that store-house and barn timbers 
sometimes give way under heavy loads of grain, which 
have appeared at first to stand with firmness. 



30 MECHANICS. 

Although the preceding table gives the strength of wood 
drawn lengthwise, yet the comparative results are not 
greatly different when the force is applied in a transverse 
or side direction, so as to break in the usual way. 

The following table shows the results of several experi- 
ments with pieces of wood one foot in length, one inch 
square, with the weight suspended from one end, breaking 
them sidewise. 

White oak, seasoned, broke with 240 lbs. 

Chestnut, " " 170 " 

White pine, " " 135 " 

Yellow pine, " " 150 " 

Ash, « " 175 " 

Hickory, « " 270 " 

A rod of good iron is about ten times as strong as the 
best hemp rope of the same size. The best iron wire is 
nearly twenty times as strong as a hemp cord. Hence the 
enormous strength of the wire cables, several inches in di- 
ameter, which are employed for the support of suspension 
bridges. 

A rope one inch in diameter will bear about 5000 lbs., 
but in practice should not be subjected to more than half 
this strain, or about one ton. The strength increases or 
diminishes according to the size of the cross-section of the 
rope ; thus a cord half an inch in diameter will support 
one quarter as much as an inch, and a quarter-inch cord a 
sixteenth as much. A knowledge of the strength of 
ropes, as used by farmers in windlasses, pulleys, drawing 
loads, etc., would sometimes prevent serious accidents. 
The following table may therefore be useful : 

Diameter of rope or Pounds borne Breaking 

cord in inches. with safety. weight. 

One-eighth 31 lbs. 78 lbs. 

One-fourth 125 " 314 " 

One-half 500 " 1250 " 

One 2000 " 5000 " 

One and a quarter 3000 " 7500 " 

One and a half 4500 " 12,500 " 



STRENGTH OF MATERIALS. 31 

These results will vary about one-fourth with the qual- 
ity of common hemp. Manilla is about one-half as strong 
as the best hemp. The latter stretches one-fifth to one- 
seventh before breaking. 

Wood is about seven to twenty times stronger when 
taken lengthwise with the fibres than when a side force is 
exerted, so as to split it. The splitting of timber or wood 
for fuel is, however, accomplished with a comparatively 
small power by the use of wedges, the force of heavy 
blows, and the leverage of the two parts. 

The attraction of cohesion is very weak in liquids ; it is 
sufficient, however, to give a round or spherical shape to 
very small portions or single drops, and to furnish a 
beautiful illustration, on a minute scale, of the same prin- 
ciple which gives a rounded form to the surface of the 
sea. In one case, cohesion, by drawing toward a common 
centre, forms the minute globule of dew upon the blade 
of grass ; in the other, gravitation, acting in like manner, 
but at vast distances, gives the mighty rotundity to the 
rolling waters of the ocean. 



CAPILLARY ATTRACTION. 

Capillary attraction is a species of cohesion ; it takes 
place only between solids and liquids. It is this which 
holds the moisture on the surface of a wet body, and which 
prevents the water from running instantly out of a wet 
cloth or sponge. By touching the lower extremity of a 
lump of sugar to the surface of water in a vessel, capillary 
attraction will cause the water to rise among its granules 
and moisten the whole lump. It may be very distinctly 
shown by placing the end of a fine glass tube into water; 
the water will rise in it above the level of the surrounding 
surface. If the bore of the tube be the twelfth of an inch 



32 



MECHANICS. 



in diameter (a, fig. 15,) it will rise a quarter of an inch ; 
if but the twenty-fifth of an inch in bore, as b, it will rise 
half an inch ; but if only a fiftieth of an inch, the water 
will rise an inch. This ascent of the liquid is caused by 
the attraction of the inner surface of the tube, until the 
weight of the column becomes equal to the force of the 
attraction. Capillary attraction may be also exhibited by 

Fig. 16 





Capillary attraction in tubes. 



Capillary attraction between two panes of 
glass. 



two small plates of glass, placed with their edges in wa- 
ter, in contact on one side, and a little open at the 
other side, as in fig. 16. As the faces of the plates ap- 
proach each other, the water rises higher, forming the 
curve, a. 

Capillary attraction performs many important offices 
in nature. The moisture of the soil depends greatly upon 
its action. If the soil is composed of coarse sand or grav- 
el, the interstices are large, and, like the larger glass tube, 
will not retain the rain which falls upon it. Such soils 
are, therefore, easily worked in wet weather, but become 
too dry in seasons of drought ; but when the texture is 
finer, and especially if a due proportion of clay be mixed 
with the sand, the interstices become exceedingly small, 
and retain a full sufficiency of moisture. If, however, 
there is too much clay, the soil is apt to become close and 
compact, and the water can not enter until it is broken up 



EARTH A DESERT WITHOUT CAPILLARY ATTRACTION. 



or pulverized. It is for this reason that subsoil plowing 
becomes so eminently beneficial, by deepening the mellow 
portion, and thus affording a larger reservoir, which acts 
like a sponge in holding the excess of falling rains, until 
wanted in the dry season. For the same reason, a well- 
cultivated soil is found to preserve its moisture much bet- 
ter during the heat of summer than a hardened and neg- 
lected surface. 

If capillary attraction should cease to exist, the earth 
would soon become a barren and uninhabitable waste. 
The moisture of rains could not be retained by the parti- 
cles of the soil, but would immediately sink 
far down into the earth, leaving the surface 
at all times as dry and unproductive as a 
desert ; vegetation would cease ; brooks and 
rivers would lose the gradual supplies which 
the earth affords them through this influence, 
and become dried up ; and all plants and all 
animals die for want of drink and nourish- 
ment. Thus the very existence of the whole 
human race evidently depends on a law, ap- 
parently insignificant to the unthinking, but 
pointing the observing mind to a striking 
proof of the creative design which planned all the works 
of nature, and fitted them with the utmost exactness for 
the life and comfort of man. 




Apparatus ex- 
plaining the 
rising of sap. 



ASCENT OF SAP. 



The following interesting experiments serve to explain 
the cause of the ascent of sap in plants and trees : 

Take a small bladder, or bag made of any similar sub- 
stance, and fasten it tightly on a tube open at both ends 
(fig. 17) ; then fill them with alcohol up to the point C, 
and immerse the bladder into a vessel of water. The al- 
cohol will immediately rise slowly in the tube, and if not 



o* 



34 MECHAXICG. 

more than two or three feet high, will run over the top. 
This is owing to the capillary attraction in the minute 
pores of the bladder, drawing the water within it faster 
than the same attraction draws the alcohol outward. One 
liquid will thus intrude itself into another with great 
force. A bladder filled with alcohol, with its neck tightly 
tied, will soon burst if plunged under water. If a blad- 
der is filled with gum-water, and then immersed as before, 
the water will find its way within against a very heavy 
pressure. 

In this manner sap ascends through the minute tubes in 
the body of trees. The sap is thickened like gum-water 
when it reaches the leaves, and a fresh supply, therefore, 
enters through the pores in the spongelets of the roots by 
capillary attraction, and, rising through the stem, keeps 
up a constant supply for the wants of the growing tree. 

CENTRE OE GEAVITY. 

The centre of gravity is that point in every hard sub- 
stance or body, on every side of which the different parts 
exactly balance each other. If the body be a globe or 
Fig. 18. round ball, the centre of 

gravity will be exactly at the 
centre of the globe ; if it be 
a rod of equal size, it will be 
at the middle of the rod. If 
a stone or any other sub- 
stance rest on a point directly under the centre of gravity, 
it will remain balanced on this point ; but if the point be 
not under the centre of gravity, the stone will fall toward 
the heaviest side. 

Some curious experiments are performed by an ingenious 
management of the centre of gravity. A light cylinder 
of cork or pasteboard contains a concealed piece of lead, 
g (fig. 18). The lead, being heavier than the rest, will 




CENTRE OF GRAVITY. EXPERIMENTS. 



35 



cause the cylinder to roll up an inclined plane, when 
placed as shown by the lower figure on the preceding en- 



graving, until it makes half a revolu- 
tion and reaches the place of the up- 
per figure, when it will remain sta- 
tionary. If a curved body, as shown 
in fig. 19, be loaded heavily at its 
ends, it will rest on the stand, and 
present a singular appearance by not 
falling, the centre of gravity lying 
between the two heavy portions on 
the end of the stand. A light stick 
of some length may be made to stand 
on the end of the finger, by sticking 
in two penknives, so as to bring the 
centre of gravity as low as the 



Fig. 19. 




Body singularly balanced by 
lead knobs. 

finger-end (fig. 20). 



If any body, of whatever shape, be suspended by a 

hook or loop at its top, it will 
necessarily hang so that the 
centre of gravity shall be di- 
rectly under the hook. In this 
way the centre in any substance, 
no matter how irregular its shape 
may be, is ascertained. Sup- 
pose, for instance, we have the 
irregular plate or board shown 
in the annexed Fig. 21. 

figure (fig. 21) : 
first hang it by 
the hook a, andtf^ 
the centre of 
gravity will be 
in 

the dotted line a b. Then hang it by the hook c, and it 
will be somewhere in the line c d. Now the point e, where 
they cross each other, is the only point in both, conse- 




Centre of gravity maintained by two 

penknives. somewhere 




36 



MECHANICS. 



quently this is the centre sought. If the mass or body, 
instead of being flat like a board, be shapeless like a stone 
or lump of chalk, holes bored from different suspending 
points directly downward will all cross each other exactly 
at the centre of gravity. 



LINE OF DIRECTION. 



Fig. 22. 



Fig. 23. 




Centre of gravity on level and inclined 
roads. 



An imaginary line from the centre of gravity perpendic- 
ularly downward to where the body rests is called the 
line of direction. 

Now in any solid body whatever, whether it be a wall, 
a stack of grain, or a loaded wagon, the line of direction 
must fall within the base or part resting upon the ground, 

or it will immediately be 
thrown over by its own 
weight. A heavily and even- 
ly loaded wagon on a level 
road will be perfectly safe, be- 
cause the line of direction falls 
equally between the wheels, 
as shown in fig. 22, by the 
dotted line, c, being the centre. But if it pass a steep side- 
hill road, throwing this line outside the wheels, as in fig. 23, 
it must be instantly overturned. If, however, instead of 
the high load represented in the figure, it be some very 
heavy material, as brick or sand, so as not to be higher 
than the square box, the centre will be much lower down, 
or at 5, and thus, the line falling within the wheels, the 
load will be safe from upsetting, unless the upper wheel 
pass over a stone, or the lower wheel sink into a rut. 
The centre of gravity of a large load may be nearly ascer- 
tained by measuring with a rod ; and it may sometimes 
happen that by measuring the sideling slope of a road, all 
of which may be done in a few minutes, a teamster may 
save himself from a comfortless upsetting, and perhaps 



CENTEE OP GEAVITY. LOADING WAGONS. 



37 



Fig. 24 




heavy loss. Again, a load may be temporarily placed so 
much toward one side, while passing a sideling road, as 
to throw the line of direction considerably more up hill 
than usual, and save the load, which may be adjusted 
again as soon as the dangerous point is passed. This 
principle also shows the reason why it is safer to place only 
light bundles of merchandise on the top of a stage-coach, 
while all heavier articles are to be down near the wheels ; 
and why a sleigh will be less likely to upset in a snow- 
drift, if all the passengers will sit or lie on the bottom. 
When it becomes necessary 
to build very large loads 
of hay, straw, wool, or 
other light substances, the 
"reach," or the long con- 
necting-bar of the wagon, 
must be made longer, so as 

tO increase the length of the Centre of gravity of an evenand one-sided 

load ; for, by doubling the 

length, two tons may be piled upon the wagon with as 

much security from upsetting as one ton only on a short 

wagon. 

Where, however, a high load can not be avoided, great 
care must be taken to have it evenly placed. If, for in- 
stance, the load of hay represented by fig. 24 be skillfully 
built, the line of direction will fall equally distant within 
each wheel ; but a slight misplacement, as in fig. 25, will 
so alter this line as to render it dangerous to drive except 
on a very even road. 

Thus every one who drives a wagon should understand 
the laws of nature sufficiently to know how to arrange 
the load he carries. It is true that experience and good 
judgment alone will be sufficient in many cases; but no 
person can fail to judge better, with the reasons clearly, 
accurately, distinctly before his eyes, than by loose con- 
jecture and random guessing. 



38 



MECHANICS. 




Zi. 



Every farmer who erects a wall or building, every team- 
ster who drives a heavy load, or even he who only carries a 
heavy weight upon his shoulder, may learn something use- 
ful by understanding the laws of gravity. 

It is familiar to every one, that a body resting upon a 
broad base is more difficult to upset than when the base 
is narrow. For instance, the square 
block (fig. 26) is less easily thrown 
over than the tall and narrow block 
of equal weight, because, in turning 
the square block over its lower edge, 
the centre of gravity must be lifted 
up considerably in the curve shown 
by the dotted line c y but with a tall, 
narrow block, this curve being almost 
on a level, very little lifting is re- 
quired. Hence the reason that a high load on a wagon is 
so much more easily overturned than a low one. 

Of all forms, a pyramid stands the most firmly on its 
base. The centre of gravity, c (fig. 26), being so near the 
broad bottom, it must be elevated in a very steep curve 
to throw the line of direction beyond the base. For this 
reason, a stone wall, or the dam for a stream, will stand 
better when broad at bottom and tapering to a narrow top 
than if of equal thickness throughout. 

When a globe or round ball is placed upon a smooth 
floor, it rests on a single point. If the Fig. 27. 

floor be level, the line of direction will 
fall exactly at this resting-point (fig. 
27). To move the ball, the centre will 
move precisely on a level, without be- 
ing raised at all. This is the reason 
that a ball, a cylinder, or a wheel is rolled forward so 
much more easily than a flat-sided or irregular body. In 
all these cases, the line of direction, although constantly 




CENTRE OF GRAVITY. — EXAMPLES. 



39 




changing its place, still continues to fall on the very point 
on wnich the round body rests. 

But if the level floor is exchanged for a slope or inclin- 
ed plane (fig. 28), the line of direc- Fig 28. 
tion no longer falls at the touchinsr- 



poi-nt, but on the side from it down- 



ward ; the ball will therefore, by its 
mere weight, commence rolling, and 
continue to do so until it reaches the 
bottom of the slope. 

Wheel-carriages owe their comparative ease of draught 
to the fact that the centre of gravity in the load is moved 
forward by the rolling of the wheels, on a level, or paral- 
lel with the surface of the road, just in the same way that 
the round ball rolls so easily. Each wheel supporting its 
part of the load at the hub, the same rule applies to each 
as to a ball or cylinder alone. Hence, on a level road, the 
line of direction falls precisely where the wheels rest on 
the ground, but if the road ascend or descend, it falls else- 
where ; this explains the reason why it will run by its own 
weight down a slope. 

Whenever a stone or other obstruction occurs in a road, 

it becomes requisite to raise the 

centre by the force of the team 

and by means of oblique motion, 

so as to throw the wheel over it, 

as shown by fig. 

29. One of the 

reasons thus. 

becomes very 

plain why a 

laro;e wheel will 



Fig. 29. 




run with more ease on a rough road than a smaller one ; 
the larger one mounting any stone or obstruction without 
lifting: the load so much out of a level or direct line, as 
shown by the dotted lines in the annexed figures, (figs. 29 



40 



MECHANICS. 




A firmly- set fruit-ladder 



A dangerous- 
ly-set fruit- 
ladder. 



and 30). Another reason is, the large wheel does not 
sink into the smaller cavities in the road. 

A self-supporting fruit-ladder (fig. 31) (the centre of 
gravity, when in use, being at or near the top) must have 

its legs more widely 
spread, to be secure from 
falling, than if the centre 
were lower down. Hence 
such a position, as in fig. 
32, would be unsafe. 

The support of the 
human body, in standing 
and walking, exhibits 
some interesting exam- 
ples in relation to this 
subject. A child can not learn to walk until he acquires 
skill enough to keep his feet always in the line of direc- 
tion. When he fails to do this, he topples over toward 
the side where the line falls outside his feet. A man stand- 
ing with his heels touching the wash-board of a room can 
not possibly stoop over without falling, because, when he 
bends, the line of direction falls forward 
of his toes, the wall against which he 
stands preventing the movement of his 
body backward to preserve the balance. 

In walking, the centre rises and falls 
slightly at each step, as shown by the 
waved line in fig. 33. If it were not 
for the bending of the knee-joints, this 
exercise would be much more laborious, 
as it would then become needful to 
throw the centre into an upward curve at every step. 
For this reason, a wooden leg is more imperfect than the 
natural one (fig. 34). Hence the reason why walking on 
crutches is laborious and fatiguing, because at every on- 



Fig. 33. 




Fiff. 34. 




CENTRE OF GRAVITY. — EXAMPLES. 



41 



Fig. 35. 



Fie-. 36. 




ward step the body must be thrown upward in a curve, 
like a wagon mounting repeated obstructions. 

When a load is carried on the shoulder, it should be so 
placed that the line of direction may pass directly through 

the shoulder or back down to the 
feet, fig. 35. An unskillful person 
will sometimes place a bag of grain 
as shown in fio\ 36. The line falling: 
outside his feet, he is compelled to 
draw downward with great force on 
the other end of the bag. A man who 
carries a heavy pole on his shoulder should see that the 
centre is directly over his slioulder, otherwise he will be 
compelled to bear down upon the lighter end, and thus 
add in an equal degree to the weight upon his body. 

If an elliptical or oval body, fig. 37, rest upon its side 
a, rolling it in either direction elevates Fig. 37. 

the centre, c, because it is nearest the 
side on which the body rests. If, 
when raised, it be suffered to fall, its 
momentum carries it beyond the 
point of rest, and thus it continues 
rocking until the force is spent. The 
course of the centre during these mo- 
tions is shown by the curved dotted 
line, c. If it be placed upon end, as in fig. 38, then any 
motion toward either side brings the centre of gravity 

nearer the touching-point, that is, 
causes it to descend, and the body 
consequently falls over on its side. 
This may be easily illustrated with 
an egg, which will lie at rest upon its 
side, but falls when set on either end. 
The rockers of chairs, cradles, 
and cribs, are formed on the princi- 
If so made that the centre of gravity 




Fig. 38. 




pie just explained. 



42 MECHANICS. 

of the chair or cradle is nearer the middle of the rocker 

than to the ends, the rocking motion will take place ; and 

when the distance from the centre of gravity to the ends 

_,. „ n w . ,„ of the rockers is but little greater 

Fi£. 39. Fig. 40. > # to 

than the distance to the middle, c, 
as in fig. 39, the motion will be 
slow and gentle ; but if this differ- 
ence be greater, as in fig. 40, it will 
be rapid. When the centre is high, 
the rockers must have less curvature 
than where it is low and near the floor. If the centre of 
gravity be nearer the ends than to the middle, the chair 
will immediately be overturned. This principle should 
be well understood in the construction of every thing 
which moves by rocking. 




CHAPTER IV. 

SIMPLE MACHINES, OR MECHANICAL POWERS. 
ADVANTAGES OE MACHINES. 

The moving forces which are applied to various useful 
purposes commonly require some change in velocity, 
direction, or mode of acting, before they accomplish the 
desired end. For example, a running stream of water has 
a motion in one direction only ; by the use of machinery, 
we change this to an alternating motion, as in the saw of 
the saw-mill, or to a rotatory or whirling motion, as in the 
stones of a grist-mill. The direct or straightforward 
power of a yoke of oxen is made, by the employment of 
the plow, to produce a side-motion to the sod, as well as 
to turn it through half a circle. The thrashing-machine 



. 



SIMPLE MACHINES, OR MECHANICAL POWERS. 43 



converts the slowly-acting pace of horses to the swift hum 
of the spiked cylinder. 

Any instrument used for thus changing or modifying 
motion is called a machine, whether it be simple or com- 
plex in its structure. Thus even a crow-bar, used in lifting 
stones from the earth, by diminishing the motion given by 
the hand and increasing its power, may be strictly termed 
a machine; while a harrow, which neither alters the 
course nor changes the velocity of the force applied, may 
with more propriety be regarded as simply an implement 
or tool. In common language, however, these distinctions 
are not accurately observed, and a machine is usually con- 
sidered to be any instrument consisting of different mov- 
ing parts. 

All machines, however complex, may be resolved into 
two simple parts, or powers. These are, 

1. The Lever ; 

2. The Inclined Plane. 

The wheel and axle, and the pulley are modified ap- 
plications of the lever ; and the wedge and the screw of 
the inclined plane, as will be shown on the following 
pages. These six are usually termed the mechanical 
powers. As they really do not possess any power in 
themselves, but only regulate power, the term " simple 
machines " may be regarded as most correct. 

THE LAW OF VIRTUAL VELOCITIES. 

Before proceeding to the simple machines, it may be 
well to explain a very important truth, which should be 
considered as lying at the foundation of all mechanical 
philosophy, and which renders plain and simple many things 
which would otherwise seem strange or contradictory. 
This is, that the force required to lift any given body is 
always in proportion to the weight of that body, taken 



44 MECHANICS. 

together with the height to be raised. For instance, it 
requires twice the force to raise two pounds as to raise 
one pound, three times the force to raise three pounds, 
and so forth. Also, twice as great a force is needed to 
elevate any weight two feet as one foot, or three times as 
great for three feet, and so on. Again, combining these 
together, four times as great a force is required to raise 
two pounds to a height of two feet as to raise one pound 
only one foot ; eight times as great for four feet, and so 
on. This holds true, no matter by what kind, of ma- 
chinery it is accomplished. Now this may all seem very 
simple, but it serves to explain many difficult questions in 
relation to the real power possessed by all machines. 

Take another example. Suppose that one wishes to 
raise a weight of 1000 pounds to a height of one foot. If 
his strength is equal to only 100 pounds, the weight 
would be ten times too heavy for him. He might, there- 
fore, divide it into ten equal parts of 100 pounds each. 
Raising each part separately the required height of one 
foot would be the same as raising one of them ten feet 
high. The weight is lessened ten times, but the distance 
is increased ten times. But there are some bodies, as, for 
example, blocks of stone or sticks of timber, which can not 
well be divided into parts in actual practice. He there- 
fore resorts to a machine or mechanical power, through 
which the same result is accomplished by raising the 
whole weight in one mass with his single strength ; but in 
this case as well as the other, the moving force which he 
applies must pass through ten times the space of the 
weight. We arrive, therefore, at the general rule, that the 
distance moved by the weight is as much less than that 
moved by the power as the power is less than the weight. 
This rule is termed by some writers the " rule of virtual 
velocities" virtual meaning not apparent or actual, but 
according to the real effect, because the increase in 
the velocity of the power makes up for increase in the size 



THE LEVEE. 45 

of weight. This rule will be better understood after con- 
sidering its application to the different simple machines. 

The simplest of all machines is the lever. It consists of 
a rod or bar, one end resting upon a prop or fulcrum, F 
(fig. 41), near which is the weight, W, moved by the 
hand at P. The stone may weigh 1000 pounds; yet, if it 
is ten times as near the fulcrum as the man's hand is, a 
force of 100 pounds will lift it ; but it will be moved only 
a tenth part as high as the hand has been moved, as shown 

Fifr41. 



Lever of the second kind. 

by the dotted lines. By placing the stone still nearer the 
fulcrum, still less will be the power required to raise it, 
but then the distance elevated would be also still less. By 
sufficiently increasing the disproportion between the two 
parts of the lever, the strength of a child merely might 
be made to move more than many horses could draw. 

These performances of the lever often excite astonish- 
ment at what appears to be out of the common course of 
things ; yet, when examined by the principles of mechan- 
ics, instead of appearing matters of astonishment, they are 
found to be only the natural and necessary results of the 
laws of force. In the case of the lever just described, it is 
often incorrectly supposed that the power itself sustains 
the weight. But this is not the case ; nearly the whole 
of it rests upon the fulcrum. We often see proofs of this 
error in common practice, where fulcrums or props entirely 
insufficient to uphold the enormous weight to be raised 
are attempted to. be used. If the weight, for instance, be 
ten times as near the fulcrum as to the power, then nine- 
tenths of the weight rests upon the fulcrum, and the re- 




ierer of tlie first kind. 



4Q MECHANICS. 

maining tenth only is sustained by the lifting power. 
The lever only allows the power to expend itself through 
a longer distance, and thus, by concentrating itself at the 
weight, to elevate the latter through the shorter distance, 
according to the rule of virtual velocities already ex- 
plained. 

The fulcrum may be placed between the weight and the 
Fig. 42. power, as in fig. 42, 



or the power may be 
placed between the 
fulcrum and the 
weight, as in fig. 43, 
the same principle of virtual velocities applying in all cases. 
Where the fulcrum is between the power and the 
weight, as in fig. 42, it is called a lever of the first hind. 
Where the weight is between the fulcrum and the 
power, as in fig. 41, it constitutes a lever of the second 
Icind. 

Where the power is between the fulcrum and the 
weight, as in fig. 43, it is termed a lever of the third 
kind. 

1. Many examples occur in practice of levers of the first 
kind. A crow-bar, used to raise stones from the earth, is 
an instance of this sort ; 
so is a handspike of 
any kind used in the 
same way. A hammer 

n ■, ., Lexer of the third kind. 

tor drawing a nail 

operates as a lever of the first kind, the heel being the ful- 
crum, the nail the weight, and the hand the power; the 
distance through which the handle passes being several 
times greater than that of the claws, the force exerted on 
the nail is increased in like proportion. A pair of scissors 
consists of two levers, the rivet being the fulcrum ; and in 
using them, as every one has observed, a greater cutting 
force is exerted near the rivets than toward the points. 




THE LEVER. EXAMPLES. 47 

This is owing to the power being expended through a 
greater distance near the points, according to the rule al- 
ready explained. Pincers, nippers, and other similar in- 
struments are also double levers of the first kind. 

A common steelyard is another example, the sliding 
weight becoming gradually more effective as it is moved 
further from the fulcrum or hook supporting the instru- 
ment. The brake or handle of a pump is a lever of this 
class, the pump-rod and piston being the weight. 

The common balance is still another, the two arms being 
exactly equal, so that one weight will always balance the 
Pig. 44. other, and on this its usefulness 

and accuracy entirely depend. 
The most sensitive balances have 
light beams with long arms, and 
the turning-point of hardened 
steel or agate, in the form of a 
faiiiiiiiiiiiiiniiiiiiiwii)iuiimiriiiiii;iimiiiiii:iii!iii.iiii;iiimiii,wi;iiiiuiiii ! iMA thin wedge, on which the balance 
turns almost without friction. Small balances have been 
so skillfully constructed as to turn with one-thousandth 
part of a grain. 

2. Levers of the second kind are less numerous, but not 
uncommon. A handspike used for rolling a log is an ex- 
ample. A wheel-barrow is a lever of the second kind, the 
fulcrum being the point where the wheel rests on the 
ground, and the weight the centre of gravity of the load. 
Hence, less exertion of strength is required in the arm 
when the load is placed near the wheel, except where the 
ground is soft or muddy, when it is found advantageous 
to place the load so that the arm shall sustain a consider- 
able portion, to prevent the wheel sinking into the soil. 
A two-wheeled cart is a similar example ; and, for the same 
reason, when the ground is soft, the load should be placed 
forward toward the horse or oxen ; on the other hand, on 
a smooth and hard, or on a plank road, the load should be 




48 



MECHANICS. 



more nearly balanced. An observance of this rule would 
often save a great deal of needless waste of strength. 

A sack-barrow, used in barns and mills for conveying 

heavy bags of grain from one part of the floor to another, 

Fig. 45. and in warehouses 

for boxes, is a lever 
nearly intermediate 
between the first and 
second kind, the 
weight usually rest- 
ing very nearly over 
the fulcrum or 
wheels. When the 
bag of grain is 
thrown forward of 
the wheels, it be- 
comes a lever of the 
first kind ; when 
back of the wheels, 
it is a lever of the 
second kind. As it 
is used only on hard 
and smooth floors, 
and not, like the wheel-barrow, on soft earth, the more 
nearly the load is placed directly over the wheels, the 
more easily they will run. 

3. In a lever of the third kind, the weight being further 
from the fulcrum than the power, it is only used where 
great power is of secondary importance when com- 
pared with rapidity and dispatch. A hand-hoe is of this 
class, the left hand acting as the fulcrum, the right hand 
as the power, and the resistance overcome by the blade 
of the hoe as the weight. A hand-rake is similar, as well 
as a fork used for pitching hay. Tongs are double levers 
of this kind, as also the shears used in shearing sheep. 
The limbs of animals, generally, are levers of the third 




Sack-bcwow. 



ESTIMATING THE POWEB OF LEVERS. 49 

kind. The joint of the bone is the fulcrum; the strong 
muscle or tendon attached to the bone near the joint is 
the power; and the weight of the limb, with whatever re- 
sistance it overcomes, is the weight. A great advantage 
results from this contrivance, because a slight contraction 
of the muscle gives a swift motion to the limb, so import- 
ant in walking and running, and in the use of the arms. 

ESTIMATING THE POWER OF LEVERS. 

The power of any lever is easily calculated by measuring 

the length of its two arms, that is, the two parts into 

Fig. 46. which it is divided by 

,.&h the weisrht, fulcrum, 

« v^ ; - ■ ■-■ - --- ■ •- ■ - . rg i TTi j-;^ -9^'— ~^ *f and power. In a 



w\ F lever of the first kind 

:--■:'''''' if the weight and 

Lever of the first kind. power be equally dis- 

tant from the fulcrum, they will move through equal dis- 
tances, and nothing will be gained ; that is, a power of 
100 pounds will lift a weight of 100 pounds only. If the 
power be twice as far as the weight, its force will be 
doubled; if three times, it will be tripled; and so forth. 
In a lever of the second kind, if the weight be equidistant 
between the fulcrum Fig. 47. 

and power, the power c p-- : --r ; --__ 
will move through ! ; ~~~~~~~~ r -~-- rr -._ r\ 

twice the distance of ■ j ___j!L rgfe^^— , 

the weight, and the m^ 

n. . , , Lever of the second kind. 

power 01 the instru- 
ment will therefore be doubled ; if twice as far, it will be 
tripled, and so on, as shown in the annexed figures. The 
same mode of reasoning will explain precisely to what 
extent the force is diminished in levers of the third kind. 

These rules will show in what manner a load borne on 
a pole is to be placed between two persons carrying it, 
3 



50 



MECHANICS. 



If equidistant between them, each will sustain a like por- 
tion. If the load be twice as near to one as to the other, 
the shorter end will receive double the weight of the 



longer. 



For the same reason, 

Fig. 48, 




when three horses are 
worked abreast, the two 
horses placed together 
should have only half 
the length of arm of the 
main w r hiffle-tree as the 
single horse, fig. 48. 
The farmer who has a 
team of two horses un- 
like in strength, may 
thus easily know how to 
adjust the arms of the 
whiffle-tree so as to correspond with the strength of each. 
If, for instance, one of the horses possesses a strength as 
much greater than the other as four is to three, then the 
weaker horse should be attached to the arm of the whiffle- 
tree made as much longer than the other arm as four is 
to three. 

In all the preceding estimates, the influence of the 
weight of the lever has not been taken into consideration. 
In a lever of the first kind, if the thickness of the two 
arms be so adjusted that it will remain balanced on the 
fulcrum, its weight 
will have no other 
efiect than to in- 
crease the pressure 
on the fulcrum ; but 
if it be of equal 
size throughout, its longer arm, being the heavier, w T ill 
add to its power. The amount thus added will be equal 
to the excess in the weight of this arm, applied so far 
along as the centre of gravity of this excess. If, for ex- 
ample, a piece of scantling twelve feet long, a b, fig. 49, 



mv 




COMBINATION OF LEVEES. 51 

be used as a lever to lift the corner of a building, then 
the two portions, a c, e d, will mutually balance each 
other. If these be each a foot in length, the weight of 
ten feet will be left to bear down the lever. The centre 
of gravity of this portion will be at e, six feet from the 
fulcrum, and it will consequently exert a force under the 
building equal to six times its own weight, If the scant- 
ling weigh five pounds to the foot, or fifty pounds for the 
excess, this force will be equal to three hundred pounds. 

In the lever of the second kind, its weight operates 
'against the moving power. If it be of equal size through- 
out, this will be equal to just one-half the weight of the 
lever, the other half being supported by the fulcrum. 

With the lever of the third kind, the rule applied to the 
first must be exactly reversed. 

COMBINATION OF LEVERS. 

A great power may be attained without the inconven- 
ience of resorting to a very long lever, by means of a com- 
bination of levers. In fig. 
50, the small weight P, act- 




iA^ mg as a moving power, ex- 
erts a three-fold force on the 
next lever ; this, in its turn, acts in the same degree on the 
third, which again increases the power three times. Con- 
sequently, the moving power, P, acts upon the weight, 
W, in a twenty-seven-fold degree, the former passing 
through a space twenty-seven times as great as the latter. 
A combination of levers like this is employed in self- 
regulating stoves. It is in this case, however, used to 
multiply instead of to diminish motion. The expansion 
of a metallic rod by heat the hundredth part of an inch 
acts on a set of iron levers, and the motion is increased, 
by the time it reaches the draught-valve, to about one 
hundred times. 



52 



MECHANICS. 



Fig. 51. 



A more compact arrangement of compound levers is 
shown in fig. 51, where the power, P, acts on the lever 

A, exerting a force on the 
lever B five times as great as 
the power. B acts on the 
lever C with a force increased 
three times, and this, again, 
on the weight, W, with a 
four-fold force. Multiplying 
5, 3, and 4 together, the prod- 
uct is 60 ; hence a force of 
one pound "at P will support 
60 pounds at W. By gradu- 
ating (or marking into 
Itjwj ^ notches) the lever C, so that 

Compound levers. the distance is measured as 

the weight is moved along it, a compact and powerful 
steelyard for weighing is formed. 




WEIGHING MACHINE. 



A valuable combination of levers is made in the con- 
struction of the weighing machine, used for weighing cat- 
tle, wagons loaded with hay, and other heavy articles. 



Fisr. 52. 




Weighing Machine. 

The wagon rests on the platform A (fig. 52,) and this 
platform rests on two levers at W, W, which presses their 
other ends both on a central point, and this again bears on 



THE WEIGHING MACHINE. 



53 



the lever D, the other end of which is connected by means 

of an upright rod with the steelyard at F. 

There are two important points gained in this combina- 
Fig. 53. tion. In the first place, the 

levers multiply the power so 
much that a few pounds' 
weight will balance a heavy 
load of hay weighing a ton 
or more ; and, in the next, 
the load resting on both the 
levers, communicates the 
same force of weight to the 
central point, from whatever 
part of the platform it hap- 
pens to stand on : for if it 
presses hardest on one lever, 
Portable Platform Scale. it bears lighter, at a cor- 

responding rate, on the other. In practice, there are 

Fis. 54. 





Large Platform Scale. 

always two pairs, or four levers, which proceed from each 



54 



MECHANICS. 



Fig. 55. 



corner of the platform, and rest on one point at the centre. 
We have taken the two only, to simplify the explanation. 
A powerful stump-extracting machine, allowing a suc- 
cession of efforts in the use of the lever, is exhibited by- 
fig. 55. The lever, «, should be a strong stick of timber, 
furnished with three massive iron hooks, secured by bolts 

passing through, as 
represented in the 
figure. Small or 
truck wheels are 
placed at each end 
of the lever, merely 
for the purpose of 
moving it easily over 
the ground. The 
stump, b, used as a 
fulcrum, has the 
chain passing round 
near its base, while 
another chain passes 
over the top of the 
stump, c, to be torn 
out. A horse is at- 
tached to the lever 

Lever Stump Machine. at d, and, moving to 

e, draws the other end of the lever backward, and loosens 
the stump ; while in this position, another chain is made 
to connect g to A, and the horse is turned about, and draws 
the lever backward to i, which still further increases the 
loosening ; a few repetitions of this alternating process 
tear out the stump. Very strong chains are requisite for 
this purpose. Large stumps may require an additional 
horse or a yoke of oxen. Where the stumps are remote 
from each other, iron rods with hooks may be used to 
connect the chains. 

The power which may be given to this and to all other 




A WILD THE0EY. 



55 



Fi" 56. 



modes of using the lever, as we have already seen, depends 
on the difference between the lengths of its two arms. A 
yoke of oxen, drawing with a force of 500 pounds on the 
long arm of a lever 25 feet long, will exert a force on the 
short arm of six inches equal to 50 times 500 pounds, or 
25,000 pounds, on the stumj). 

It was after an examination of the great power which 
may be given to the lever by increasing this difference 
that Archimedes exultingly exclaimed, " Give me but a 
fulcrum whereon to place my 
lever, and. I will move the earth !" 
Admitting the theoretical truth of 
this exclamation, and supposing 
there could be a lever which he 
might have used for this purpose, 
its practical impossibility may be 
quickly understood by computing 
the whole bulk of the globe ; for 
such is its enormous size and cu- 
bical contents, that Archimedes 
must have moved forward his 
lever with the strength of a hun- 
dred pounds and the swiftness 
of a cannon ball for eight hundred million years to have 
moved the earth the thousandth part of an inch ! 




WHEEL AND AXLE. 



In treating of the lever, it was shown to be capable of 
exerting a force through a small distance only. Hence, 
if a heavy body were required to be elevated to any con- 
siderable height, it would be necessary to accomplish it 
by a succession of efforts. This inconvenience is removed 
by a constant and unremitted action of the lever in the 
form of the wheel and axle. 

Let the weight, w (fig. 56,) be suspended by a cord 



56 



MECHANICS. 



from the end of the lever, a &, and a, wheel attached to 
the lever, so that this cord may wind upon it as the 
weight is elevated ; then let the power be applied at the 
other end by means of a cord, and a larger wheel be at- 
tached, so that this cord too may wind upon the larger 
wheel. These two wheels (fastened together so as to 
form one), as they are made to revolve on their axis, will 
now constitute, in a manner, a succession of levers, acting 
through an indefinite distance according to the length of 
the cords. The levers here successively acting are of the 
" first kind," and the axis of the wheel is the fulcrum. 
This arrangement constitutes in substance the wheel and 
axle ; and its power, like that of the simple lever, depends 
on the comparative velocity of the weight and the moving 
force. If, for example, the larger wheel is four times the 
circumference of the smaller, a force of one hundred applied 
to the outer cord will raise a weight of four hundred 
pounds. 

The annexed figure exhibits at one view the power ex- 
erted through the 
wheel and axle, where 
a small weight of C 
pounds wall wind up 
(or balance) other 
w r eights separately, 
weighing 8, 12, or 24 
pounds, as the differ- 
ence increases between 
the size of the wheel 
and of the axle, ac- 
cording to the rule of 
virtual velocities already explained. 

The thickness of the rope has not been taken into con- 
sideration. This is very small when compared with the 
diameter of the outer wheel, but often considerable when 
compared with that of the inner. To be strictly accurate, 



Fig. 57. 




Wheel and axle, showing the heavier weight for 
less motion. 



WHEEL AND AXLE. EXAMPLES. 57 

therefore, the force must be considered as acting at the 
centre of the rope ; hence the diameter of the rope must 
be added to the diameter of the wheel. 

There are various forms of the wheel and axle. In the 
common windlass, motion is given to the axle by means of 
a winch, which is a lever like the handle of a grindstone. 
The windlass used in digging wells has usually four pro- 
jecting levers or arms. The wheel used in steering a ves- 
sel is furnished with pins in the circumference, to which 
the hand is applied in turning it. In the capstan (for 
weighing anchor) the axis is vertical, and horizontal levers 
are applied around it, so that several men may work at 
once. The power of all these forms is easily calculated 
by the rule of virtual velocities — that is, that the velocity 
with which the power moves is as many times greater 
than the velocity of the weight, as the weight exceeds the 
power. A simple and convenient rule for computing in 
numbers the power of wheel-work is the following : Multi- 
ply all the numbers together which express either the cir- 
cumferences or diameters of the large wheels, and then 
multiply together all the numbers which express the diam- 
eters of the smaller wheels or pinions; divide the greater 
number by the less, and the quotient will be the power 
sought. 

BAND AND COG WHEELS 

Where great power is required, several wheels and 
axles may be combined in a man- Fig. 59. 

ner corresponding with that of the 
compound system of levers already 
explained. In this case the axis of 
one wheel acts on the circumference 
of the next, producing a continued 
slower motion, and increasing the 
power in a corresponding degree. Combined cog-wheels. 
The wheels are made thus to act by means of cogs or teeth, 
3* 




58 



MECHANICS. 



Fig. 60. 



or of bands (fig. 59). In ordinary practice, however, com- 
bined wheels are made use of to multiply motion instead 
of to diminish it, familiar instances of which occur in the 
grist-mill and thrashing machine. 

In connecting a system of w T heels, the cord or strap 
may be used where great force is not required, the friction 
round the circumference being sufficient to prevent slip- 
ping. Bands are chiefly useful where motion is to be 
transmitted to a distance ; as, for example, from a horse- 
power without a barn to a thrashing-machine within it. 

Liability of sliding is some- 
times useful, by preventing 
the machinery from breaking 
when a sudden obstruction 
occurs. Where the force is 
great, the necessary tension or 
tightness of the cord produces 
too great a friction at the 
axle. In such cases, cogs or 
teeth must be resorted to. 
The term teeth is usually 
applied when they are formed 
of the same piece as the 
wheel, as in the case of cast- 
iron wheels. Cogs are teeth 
formed separately and inserted into the wheel, as with 
wooden wmeels. Pinions are the small wheels, or, more 
properly, teeth set on axles. 




Form of cogs— a, badly formed ; 
b, proper form. 



FORM OF TEETH OR COGS. 



The form of the teeth has a great influence on the 
amount of friction among wheel-work. Badly formed 
teeth are represented by the wheel-work at a, in the an- 
nexed figure, consisting of square projecting pins. When 
these teeth first come into contact with each other, they 



FORM OF TEETH OR COGS, 



59 



Fig. 61. 



act obliquely together, and thus a part of their force is lost, 
and they continue scraping together with a large amount 
of friction so long as they remain in contact. These 
effects are avoided by giving to them the curved form, 
represented by b. Here, instead of pressing each other 
obliquely, they act at right angles, that is, not obliquely, 
and instead of scraping, they roll over each other with 
ease. These curves are as- 
certained by mathemat- 
ical calculation, which 
can not be here given ; 
it may be enough to state 
that they should be so 
formed that the points 
in contact shall always 
work at right angles to 
each other. For ordi- 
nary practical purposes 
as shown in the annexed 



y-~- 




Mode of giving the best form to cogs. 

however, they may be made 
tne annexed figure (fig. 61), by striking 
circles whose diameters shall embrace just three teeth. 
The points of the teeth thus formed are removed, leaving 
a blunt extremity, according to the figure. 

There are a few other rules that should always be ob- 
served in constructing wheel-work, in order that the 
wheels may run easily together, without jerking o? rat- 
tling, the most important of which are the following : 

1. The teeth must be of uniform size and distance from 
each other, through the whole circumference of the wheel. 

2. Any tooth must begin to act at the same instant 
that the preceding tooth ceases to touch its corresponding 
tooth on the other wheel. 

3. There must be sufficient space between the teeth not 
only to admit those of the other wheel, but to allow a cer- 
tain degree of play, which should be equal to at least one- 
tenth of the thickness of the teeth. 

4. The pinions should not be very small, unless the 



60 



MECHANICS. 



wheels they act on are quite large. In a pinion that has 
only eight teeth, each tooth begins to act before it reaches 
the line of the centres, and it is not disengaged as soon as 
the next one begins to act. A pinion of ten teeth will 
not operate perfectly if working in a wheel of less than 72 
teeth. Pinions of less than six teeth should never be 
used. 

5. To give strength to the teeth of wheels, make the 
wheels themselves thicker, which increases the breadth of 
the teeth. 

6. Wheel-work is often defective when not made of 
uniform material, in consequence of the relative number 

Fig. 62. of teeth working together not being such as 
to equalize the wear of all alike. If the 
number of teeth on a wheel is divided with- 
out a remainder by the number of the pinion, 
then the same teeth will repeatedly engage 
each other, and they will often wear uneven- 
ly. The number should be so arranged that 

every tooth of the pinion may work in succession into the 

teeth of the wheel. This is best effected by first taking a 

number for the wheel that will be evenly 

divided by the number on the pinion, and 

then adding one more tooth to the wheel. 

This will effect a continual change, so 

that no two shall be engaged with each 

other twice until all the rest have been 

gone through with. This odd tooth is 

called the hunting-cog. 

Cog-wheels are most usually made 

with the teeth on the outside or cir- 
cumference of the wheel ; these are termed spur-icheels. 
If the teeth are set on one side of the wheels, they are 

termed crown-wheels. When they are made so as to work 

together obliquely, they are called bev el-wheels, as in fig. 62. 
Where the obliquity is small, the motion may be com- 




Bevd-icheels. 



Fig. 03. 




Universal joint. 






THE PULLET. 



Gl 



municated by means of the universal joint, as shown in 
fig. 63. This is commonly used in the thrashing-machine, 
where there is a slight change in the direction of motion 
between the horse-power and the thrasher. 



THE PULLEY. 




Pulley doubling the 
force. 



fixed at one end pass round a movable 
grooved wheel, and be grasped by the 
hand at the other end : then, in lifting 
any weight attached to the wheel, by 
drawing up the cord, the hand will move 
with twice the velocity of the weight. 
It will, therefore, exert double the degree 

Fie. 65. 



of force. This operates 
precisely as a succession of 
levers of the second kind, 
the fixed cord being the 
fulcrum, and the cord drawn 
up by the hand, the power. 
It thus constitutes one of the simplest kinds 
of the pulley, fig. 64. 

The wheel is called a sheave; the term 
pulley is applied to the block and sheave ; 
and a combination of sheaves, blocks, and 
ropes is called a tackle. 

There are various combinations of single 
pulleys for increasing power, the most com- 
mon of which, and least liable to become 
deranged by the cord being thrown off the 
wheels, is shown in fig. 65. In this and in 
all similarly constructed pulleys, the weight 
is as many times greater than the power as 
the number of cords which support the low r er block. If 
there lie six cords, as in the figure, the weight will be six 
limes the power. 




Pulley of six-fold 
power. 



62 



MECHANICS. 





Pulley with no increase of 
power. 



Where a cord is passed over a single fixed wheel, as in 

fig. 66, or over two or more wheels, no power is gained, 

Fig. 66 . the moving force being the same in 

17 velocity as the weight. Such pulleys 

are sometimes, however, of use by 

altering the direction of the force. 

The latter is applied with advantage 

to unloading or pitching hay by 

means of a horse-power, saving much 

time and labor, as explained on a 

future page. 

Among the many applications of 
the pulley, one is shown in the ac- 
companying figure (fig. 67) rep- 
resenting Packer's Stone Lifter, for 
raising large boulders from the soil, 
weighing from one to four and five 
tons, and afterwards placing them in 
Avails. It is also employed for tearing out small or partly 
decayed stumps. 

The usefulness of the pulley depends mainly upon its 
lightness and port- Fig. gt. 

able form, and the 
facility with which 
it may be made 
to operate in al- 
most any situation. 
Hence it is much 
used in building, 
and is extensively 
applied in the rig- 
ging of ships. In Packer's Stone Lifter. 
the computation of its power there is a large drawback, 
not taken into account in the preceding calculation, which 
materially lessens its advantage; this is the friction of 
the wheels and blocks and the stiffness of the cordage. 





THE INCLINED PLANE. 63 

which are often so great that two-thirds of the power 
is lost. 

THE INCLINED PLANE. 

The inclined plane or slope possesses a power which is 
estimated by the proportion which its length bears to the 
height. If, for example, the plane be twice as long as the 
perpendicular height, then in rolling the body a up the 
inclined plane (fig. G8), it will move through twice the 
distance required to lift it directly from b to c. Therefore 
only one-half the strength else required need be exerted for 
this purpose. The same reasoning Fi g . es. 

will apply to any other proportion c 
between the height and length ; 
that is, the more gradual or less 
steep the slope becomes, the greater J) 
will be the advantage gained. A familiar example occurs 
in lifting a loaded barrel into a wagon : the longer the 
plank used in rolling it, the less is the exertion needed. 

A body, in rolling freely down an inclined plane, acquires 
the same velocity that it would attain if dropped perpen- 
dicularly from a height equal to the perpendicular height 
of the plane. Thus, if an inclined plane on a plank road 
be 100 yards long and 16 feet high, a freely running 
wagon, left to descend of its own accord, will move 32 
feet per second by the time it reaches the bottom, that 
being the velocity of a stone falling 16 feet. Or, a rail- 
car on an inclined plane 145 feet high will attain a speed 
of 96 feet per second, or more than 65 miles an hour, at 
the foot of the plane, which is equal to the velocity of a 
stone falling three seconds, or 145 feet. 

ASCENT IN EOADS. - 

All roads not perfectly level may be regarded as inclined 
planes. By the application of the preceding rule, we 



64 MECHANICS. 

may discover precisely how much strength is lost in draw- 
ing heavy wagons up hill. If the load and wagon weigh 
a ton, and the road rise one foot in height to every five 
feet of distance, then the increased strength required to 
draw the load will be one-fifth of its weight, or equal to 
400 pounds. If it rise only one foot in twenty, then the 
increase in power needed to ascend this plane will be only 
100 pounds. The great importance of preserving, as 
nearly as practicable, a perfect level is obvious. 

There are many roads made in this country, rising over 
and descending hills, which might be made nearly level by 
deviating a little to the right or to the left. Suppose, for 
example, that a road be required to connect the two points 

Ffe. 69. 

Smiles b 




a and b (fig. 69), three miles apart, but separated by a 
lofty hill midway between them, and one mile in diameter. 
Passing half a mile on either side would entirely avoid 
the hill, and the road thus curved would be only one 
hundred and forty-eight yards, or one-twelfth of a mile 
longer. The same steep hill is ascended perhaps fifty to 
five hundred times a year by a hundred different farmers, 
expending an amount of strength, in the aggregate, 
sufficient to elevate ten thousand tons annually to this 
height, as a calculation will at once show — more than 
enough for all the increased expense of making the road 
level. 

It is interesting and important to examine how much 
further it is expedient to carry a road through a circuitous 
level course than over a hill. To ascertain this point, we 
must take into view the resistance occasioned by the rough 
surface or soft material of the road. Roads vary greatly 



THE RESISTANCE OF ROADS. 65 

in this particular, but the following may be considered as 
about a fair average. In drawing a ton weight (including 
wagon) on freely running wheels, on a perfect level, the 
strength exerted will be found about equal to the follow- 



ing 



On a hard, smooth plank road 40 pounds. 

On a good Macadam road 60 " 

On a common good Lard road 100 " 

On a soft road about 200 " 

Now let us compare this resistance to the resistance of 
drawing up hill. First, for the plank road — forty pounds 
is one-fiftieth of a ton ; therefore a rise of one foot in fifty 
of length will increase the draught equal to the resistance 
of the road. Hence the road might be increased fifty feet 
in length to avoid an ascent of one foot ; or, at the same 
rate, it might be increased a mile in length to avoid an 
ascent of one hundred and five feet. But in this estimate 
the increase in cost of making the longer road is not taken 
into account. If making and keeping in repair be equal 
to three hundred dollars yearly per mile, and one hundred 
teams pass over it daily, at a cost for traveling of four 
cents each per mile, being four dollars daily, or twelve 
hundred dollars per annum, then the cost of making and 
repair would be one quarter of the expense of traveling 
over it. Therefore the mile should be diminished one 
quarter in length to make these two sources of expense 
counterbalance each other. Hence a road with this 
amount of travel should, with a reference to public 
accommodation, be made three-fourths of a mile longer 
to avoid a hill of one hundred and five feet. This 
estimate applies to, loaded teams only. For light car- 
riages the advantages of the level road would not be so 
great. One-half to five-eighths of a mile would, there- 
fore, be a fair estimate for all kinds of traveling taken 
together. 



66 MECHANICS. 

The following table shows the rise in a mile of road for 
different ascents : 

For a rise of 1 foot in 10, the road ascends 528 feet per mile, 
do. 1 do. 13, do. 406 do. 



do. 


1 


do. 


15, 


do. 


352 


do. 


do. 


1 


do. 


20, 


do. 


204 


do. 


do. 


1 


do. 


25, 


do. 


211 


do. 


do. 


1 


do. 


30, 


do. 


176 


do. 


do. 


1 


do. 


35, 


do. 


151 


do. 


do. 


1 


do. 


40, 


do. 


132 


do. 


do. 


1 


do. 


45, 


do. 


117 


do. 


do. 


1 


do. 


50, 


do. 


106 


do. 


do. 


1 


do. 


100, 


do. 


53 


do. 


do. 


1 


do. 


125, 


do. 


42 


do. 






The same kind of reasoning applied to a common good 
road will show that it will be profitable for the public to 
travel about half that distance to avoid a hill of one 
hundred and five feet. In this case the whole yearly- 
cost of the road, including interest on the land, and the 
cost of repairs, would not usually be more than a tenth 
part of the same cost for plank, or would not exceed thirty 
dollars. 

On rail-roads, where the resistance is only about one- 
fifth part of the resistance of plank roads, the dispropor- 
tion between the draught on a level and up an ascent be- 
comes many times greater. Thus, if a single engine move 
three hundred and fifty tons on a level, then two engines 
will be required for an ascent of only twenty feet per 
mile, four engines for fifty feet per mile, and six engines 
for eighty feet per mile. 

Such estimates as these merit the attention of the 
farmer in laying out his own private farm roads. It may 
be worthy of considerable effort to avoid a hill of ten or 
twenty feet, which must be passed over a hundred times 
yearly with loads of manure, grain, hay, and wood. The 
greatly increased resistance of soft materials, also, is too 
rarely taken into account. A few loads of gravel, well 
applied, would often prevent ten times the labor in plow- 






FORM AND MATERIALS FOR ROADS. 67 

ing through deep ruts, to say nothing of the breaking 
of harness and wagons by the excessive exertions of the 
team. 

FORM AND MATERIALS FOR ROADS. 

The depth of the mud in common roads is often un- 
necessarily great, in consequence of heaping together 
with the plow and scraj>er the soft top-soil for the raised 

F\z. 70. 





Scclio7i of badly forined road. 

carriage-way. When heavy rains fall, this forms a deep 
bed of mud, into which the wheels work their way, and 
cause extreme labor to the team. A much better way is 
to scrape off and cart away into the fields adjoining all 
the soft, rich, upper surface, and then to form the harder 
subsoil into a slightly rounded carriage-way, with a ditch 
on each side. Such roads as this have a very hard and 
firm foundation, and they have been found not to cut up 

Fig. 71. 



Section of loett-formed road. 

into ruts, nor to form much mud, even in the wettest sea- 
sons. On this hard foundation six inches of gravel will 
endure longer and form a better surface than twelve 
inches on a raised " turnpike" of soft soil and mud. 

It frequently happens that the form of the surface in- 
creases the quantity of mud in a road, by not allowing 
the water to flow off freely. The earth is heaped up in a 
high ridge, but having little slope on the top (fig. 70), 
where the water lodges, and ruts are formed, the only dry 
portions being on the brink of the ditches, where the 
water can escape. Instead of this form, there should be a 
gradual inclination from the centre to the ditches, as 
shown in fi^. 71. This inclination should not exceed 1 



68 MECHANICS. 

foot iii 20. On hill-sides the slope should all be toward 
the higher ground, as in fig. 72. 

Hard and durable roads are made on the plan of Telford. 
Their foundation is rounded stones, placed upright, with 
the smaller or sharper ends upward. The smaller stones 

Fig. 72. 







Section of road for hillsides. 

are placed near the sides, and the larger at the centre, 
thus giving to the road a convex form. The spaces 
are then filled in with small broken stone, and the whole 
covered with the same material or with gravel. The 
pressure of wagons crowds it compactly between the 
stones, and forms a very hard mass. 

IMPORTANCE OP GOOD ROADS. 

The principles of road-making should be better under- 
stood by the community at large. Farmers are deeply 
interested in good roads. Nearness to market, and facili- 
ties for all other kinds of communication, are worth a 
great deal, often materially affecting the price of land 
and its products. The difference between traveling ten 
miles through deep mud, at two miles per hour, with half 
a load, and traveling ten miles over a fine road, at five 
miles per hour, with a full load, should not be forgotten. 

" In the absence of such facilities," says Gillespie, " the 
richest productions of nature waste on the spot of their 
growth. The luxuriant crops of our western prairies are 
sometimes left to decay on the ground, because there are 
no rapid and easy means of conveying them to market. 
The rich mines in the northern part of the State of New 



GOOD AND BAD ROADS. G9 

York are comparatively valueless, because the roads among 
the mountains are so few and so bad, that the expense of 
the transportation of the metal would exceed its value. 
So, too, in Spain it has been known, after a succession of 
abundant harvests, that the wheat has actually been 
allowed to rot, because it would not repay the cost of 
carriage." Again, " When the Spanish government re- 
quired a supply of grain to be transferred from Old Castile 
to Madrid, 30,000 horses and mules were necessary for the 
transportation of four hundred and eighty tons of wheat. 
Upon a broken-stone road of the best sort, one-hundredth 
of that number could easily have done the work." He 
further adds, in speaking of the improvements in roads 
made by Marshal Wade, in the Scottish Highlands, " His 
military road is said to have done more for the civilization 
of the Highlands than the preceding efforts of all the 
British monarchs. But the later roads, under the more 
scientific direction of Telford, produced a change in the 
state of the people which is probably unparalleled in the 
history of any country for the same space of time. Large 
crops of wheat now cover former wastes ; farmers' houses 
and herds of cattle are now seen where was previously a 
desert ; estates have increased seven-fold in value and 
annual returns ; and the country has been advanced at 
least one hundred years." 

THE WEDGE. 

The wedge is a double inclined plane, the power being- 
applied at the back to urge it forward. It becomes more 
and more powerful as it is made more acute ; but, on ac- 
count of the enormous amount of friction, its exact power 
can not be very accurately estimated. It is nearly always 
urged by successive blows of a heavy body, the momentum 
of which imparts to it great force. 

All cutting and piercing instruments, as knives, scissors, 



70 



MECHANICS. 



chisels, pins, needles, and awls, are wedges. The degree 
of acuteness must be varied according to circumstances ; 
knives, for instance, which act merely by pressure, may be 
made with a much sharper angle than axes, which strike 
a severe blow. For cutting very hard substances, as iron, 
the edge must be formed with a still more obtuse angle. 

The utility of the wedge depends on the friction of its 
surfaces. In driving an iron wedge into a frozen or icy 
stick of wood, as every chopper has observed, the want 
of sufficient friction causes it immediately to recoil, unless 
it be previously heated in the fire. The efficacy of nails 
depends entirely on the friction against their wedge-like 
faces. 

THE SCREW 




The screw may be regarded as nothing more than an 
Fig. 74 inclined plane winding round the surface of a 
j^t___jiifen cylinder (fig. 74). This may be easily under- 
stood by cutting a piece of paper in such a 
form that its edge, a b (fig. 75), may represent 
the inclined plane ; then, beginning at the wider 
end, and wrapping it about the cylindrical piece 
of wood, e, the upper edge of the paper will 
represent the thread of the screw. 
Although the friction attending the use of the screw is 

considerable, and without it it would not retain its place, 

yet the slope of its in- 
clined thread being so 

gradual, it possesses 

great power. This power 

is multijmed to a still 

greater degree by the 

lever which is usually employed to drive it, a (fig. 76). 

If, for example, a screw be ten inches in circumference, 

and its thread half an inch apart, it exerts a force twenty 



Fig. 75. 




THE SCREW. 



71 



Fig. 76. 



times as great as the moving power. If it be moved 
by a lever twenty times as long as the diameter of the 
screw, here is another increase of twenty 
times in force. Multiplying 20 by 20 
gives 400, the whole amount gained by 
this combination, and by which a man 
applying one hundred pounds in force 
could exert a pressure equal to twenty 
tons. About one-third or one-fourth of 
this should, however, be deducted for 
friction. 

When the screw is combined with the 
wheel and axle (fig. 77), it is capable of exerting great 
power, which may be readily calculated by multiplying 
the power of the screw and its lever into the power of 
the wheel and axle. 




Screw and lever 
combined. 



THE KNEE-JOINT POWER. 



Fig. 77. 



The knee-joint or toggle-joint is usually regarded as a com- 
pound lever, and consists of two rods connected by a turn- 
ing joint, as represented in fig. 78. The outer end of one of 

the levers is fixed to 
a solid beam, and the 
other connected with 
a movable block. 
When the joint a is 
forced in the direc- 
tion indicated by the 
arrow, it produces a 
powerful pressure 
upon the movable 
block, which in- 
creases as the lever approaches a straight line. This is 
easily understood by the rule of virtual velocities, for the 
force moves with a velocity many times greater than the 




Screw, lever, and wheel 
cornbiiwcl. 



Knee-joint power. 



72 



MECHANICS. 



power given to the block, and this relative difference in- 
creases as the joint is made straighter. 

This power is made use of in the lever printing-press, 
where the greatest force is given just as the pressure is 
completed. Another example occurs in the Lever Wash- 
ing-machine (fig. 79), which is worked by the alternating 
motion of the handle, A, pressing a swinging board, per- 



Fiff. 79. 




Lever Washing-machine. 



forated with holes, with great force against the clothes 
next to one side of the water-box. Like the printing- 
press, this machine exerts the greatest power just as the 
motion of the lever is completed, and at the time it is 
most needed. The same principle is exhibited in Kendall's 
Cheese-press (fig. 80), where the lever and the wheel and 
axle are combined with the two knee-joints, one on each 
side of the press, drawing down a cross-beam upon the 
cheese with a greatly multiplied power. 

Dick's Cheese-press (fig. 83), operates on a similar 
principle. Figs. 81-2 show the structure of its working 



LEVER WASHING-MACHINE. 

Pig. 80. 



73 




Fig. 82. 



KendalVs Cheese-press. 

part, the dotted lines indicating the position of the lever, 
which is inserted into a roller or axle, and, by turning, 
drives the movable iron blocks asunder, and raises the 
cheese against the broad screw-head above, as shown in 
fig. 82. In fig. 81, the raised lever shows that the blocks 
Tip-. 81. are at ^ rs<} near together, but are 
crowded asunder as the lever is press- 
ed downward. This cheese-press is 
made of cast-iron, and has great 
power; to try it, weights were in- 
creased upon the lever, until the iron 
frame broke with a force equal to six- 
teen tons. 

The power exerted by a rolling- 
mill, where bars of iron are flattened 
in their passage between two strong 
rollers, is precisely like that of the knee-joint. The only 
4 




•74 



MECHANICS. 

Fig. 83. 




Dick's cast-iron Cheese-press. 

difference is, that the rollers, which may be considered as a 
constant succession of levers coming into play as they re- 
volve, are both fixed, and consequently the bar has to yield 
between them (fig. 84). The Fig. 84. 

greatest power is exerted just 
as the bar receives the last 
pressure from the rollers. The 
most powerful and rapidly- 
working straw-cutters are those 
which draw the straw or hay 
between two rollers, one of 
which is furnished with knives 
set around it parallel with its 
axis, and cutting on the other, which is covered with un- 
tanned ox-hide (fig. 85). 




Principle of the knee-joint in the 
rolling-mill 



STRAW CUTTERS. 
Fig. 85. 



75 




Hide Boiler Straw Cutter. 



CHAPTER Y. 



APPLICATION OF MECHANICAL PRINCIPLES IN THE 

STRUCTUPvE OF SIMPLE IMPLEMENTS AND 

PARTS OF MACHINES. 

In contriving the more difficult and complex machines, 
the principles of mechanics must be closely studied, to 
give every part just that degree of strength required, and 
to render their operation as perfect as possible. But in 
making the more common and simple implements of the 
farmer, mere guess-work too often becomes the only guide. 
Yet it is highly useful to apply scientific knowledge even 
in the shaping of a hoe handle or a plow-beam. 

The simplest tool, if constantly used, should be formed 
with a view to the best application of strength. The 
laborer who makes with a common hoe two thousand 



76 MECHANICS. 

strokes an hour, should not wield a needless ounce. If 
any part is heavier than necessary, even "to the amount of 
half an ounce only, he must repeatedly and continually 
lift this half ounce, so that the whole strength thus spent 
would be equal, in a day, to twelve hundred and fifty 
pounds, which ought to be exerted in stirring the soil and 
destroying weeds. Or, take another instance : A farm 
wagon usually weighs nearly half a ton ; many might be 

Fig. 86. 
W 



C 



Badly-formed fork handle. 

reduced fifty pounds in weight by proportioning every 
part exactly to the strength required. How much, then, 
should we gain here? Every farmer who drives a wagon 
with its needless fifty pounds, on an average of only five 
miles a day, draws an unnecessary weight every year 
equal to the conveyance of a heavy wagon-load to a dis- 
tance of forty miles. 

Now a knowledge of mechanical science will often ena- 
ble the farmer, when he selects and buys his implements, 
to judge correctly whether every part is properly adapted 
to the required strength. We shall suppose, for instance, 
that he intends to purchase a common pitchfork. He 
finds them differently formed, although all are made of the 

Fig. 87. 
Os 



Badly-formed fork handle. 

best materials. The handles of some are of equal size 
throughout. Some are smaller near the fork, as in fig. 86, 
and others are larger at the same place, as in fig. 87. 
Now, if he understands the principle of the lever, he 
knows that both of these are wrongly made, for the right 
hand placed at a is the fulcrum, where the greatest 
strength is needed, and therefore the one represented by 
fig. 88 is both stronger and lighter than the others. 



PRINCIPLES IN THE STRUCTURE OF IMPLEMENTS. 77 

Again, hoe handles, not needing much strength, chiefly 
require lightness -and convenience for grasping. Hence, 
in selecting from two such as are represented in the annex- 
ed figures, the one should be chosen which is lightest near 

Fig. 88. 



Well-formed fork handle. 

the blade, nearly all the motion being in that direction, 
because the upper end is the centre of motion. The right 
hand, at «, acting partly as the fulcrum, the hoe handle 
should be slightly enlarged at that place. Fig. 89 rep- 
resents a well-formed handle ; fig. 90, a clumsy one. Rake 
handles should be made largest at the middle, or where 
the right hand presses. Rake-heads should be much 
larger at the centre, and tapering to the ends, where the 
stress is least, the two parts operating as two distinct lev- 
Fig. 89. 
a. 



Well-formed hoe handle. 

ers, acting from the middle. Wood horse-raJces might be 
made considerably lighter than they usually are by ob- 
serving the same principles. The greatest strength requir- 
ed for plow-beams is at the junction with the mould-board, 
and the least near the forward end, or furthest from the 
fulcrum or centre of motion. 

Now it may be that the farmer who has had much ex- 
perience may be able to judge of all these things without 

Fig. 90. 



c? 



Badly-formed hoe handle. 

a knowledge of the science. But this scientific knowledge 
would serve to strengthen his experience, and enable him 
to judge more accurately and understandingly by showing 
him the reasons ; and in many cases, where new imple- 
ments were introduced, he might be enabled to form a 



78 



MECHANICS. 



good judgment before he had incurred all the expense and 
losses of unsuccessful trials. 

Even so simple a form as that of an ox-yoke is often 
made unnecessarily heavy. Fig. 91 represents one that is 
faulty in this respect, by having been cut from a piece of 



Ficr. 91. 







timber as wide as the dotted lines a c / and being thus 
weakened, it requires to be correspondingly large. Fig. 
92 is equally strong, much lighter, and is easily made from 
a stick of timber only as wide as a b in the former figure. 
In the heavier machines, it is necessary to know the de- 
gree of taper in the different parts with accuracy. A 
thorough knowledge of science is needed to calculate this 

Fig. 92. 




with precision, but a superficial idea may be given by cuts. 
If a bar of wood, formed as in a (fig. 93), be fixed in a 
wall of masonry, it will possess as much strength to sup- 
port a weight hung on the end as if it were the same size 
throughout, as b. The first is equally strong with the 
second, and much lighter.* The same form doubled must 



* The simple st} Y le of this work precludes an explanation of the mode 
of calculation for determining the exact form. Where the stick taper8 
only on one side, it is a common parabola ; if on all sides, a cubic 
parabola, 



VARIOUS EXAMPLES. 



79 



be given if the bar is supported at the middle, with a 
weight at each end, or with the weight at the middle, 
supported at each end, as c. This form, therefore, is a 
proper one for many parts of implements, as the bars of 
whiffle-trees, the rounds of ladders, string-pieces of bridges, 
and any cross-beams for supporting weights. The proper 
form for rake-teeth and fence-posts, the pressure being 
nearly alike on all parts, is nearly that of a long wedge, 
or with a straight and uniform taper. Therefore a fence- 
post of equal size throughout contains nearly twice as 
much timber as is needed for strength only. 

The form of these parts must, however, be modified to 
suit circumstances ; as whiffle-trees must be large enough 

Fig. 93. 




at the ends to receive the iron hooks, wagon-tongues for 
ironing at the end, and spade handles for the easy grasp 
of the hand. 

The axle-trees of wagons must be made not only strong 
in the middle, or at centre of pressure, but also at the en- 
trance of the hub ; because the wheels, when thrown side- 
wise in a rut, or on a sideling road, operate as levers at 
that point, a and b (fig. 94), show the manner in which 
the axles of carts may be rendered lighter without lessen- 
ing the strength, a being the common form, and b the im- 
proved one. 



80 MECHANICS. 

Sometimes several forces act at once on different parts. 
For example, the spokes of wagon- wheels require strength 
at the hub for stiffening the wheel ; they must be strong 
in the middle to prevent bending, and large enough at 



the outer ends, where they are soonest weakened by de- 
cay. Hence there should be nearly a uniform taper, 
slightly larger at the middle, and with an enlargement at 
the outer end, as c (fig. 94). 

A very useful rule in practice, in giving strength to 
structures, is this : The strength of every square beam or 
stick to support a weight increases exactly as the width 
increases, and also exactly as the square of the depth in- 
creases. For example, a stick of timber eight inches wide 
and four inches deep (that is, four inches thick), is exactly 
twice as strong as another onlv four inches wide, and with 

O J 7 

the same depth. It is twice as wide, and consequently 
twice as strong ; that is, its strength increases just as the 
width increases, according to the rule given. But where 
one stick of timber is twice as deep, the width being the 
same, it is four thnes stronger ; if three times as deep, it 
is nine thnes stronger, and so on. Its strength increases 
as the square of the depth, as already stated. The same 
rule will show that a board an inch thick and twelve inch- 
es wide will be twelve times as stronsr when edgewise as 
when lying flat. Hence the increase in strength given to 
whiffle-trees, fence-posts, joists, rafters, and string-pieces 
to farm-bridges, by making them narrow and deep. 



CALCULATING THE STRENGTH OF PaF.TS. 51 

Again, the strength of a round stick increases as the cube 
of the diameter increases ; that is. a round piece of wood 

three inches in diameter is eight tunes u strong as one an 
inch and a half in diameter, and twenty-seven time- 
strong as one an inch in diameter. This rule shows that 
a fork handle an inch and a halt' in diameter at the middle 
9 much stronger than one an inch and a quarter in 
diameter, as seven is greater than four. Xcw this rule 
would enable the farmer to ascertain this without break- 
ing half a dozen fork handles in trying the experiment, 
and it would enable the manufacturer to know, without 

Kg. 95. 




the labor of trying many experiments, that if he makes a 
fork handle an inch and a half at the middle, tapering a 
quarter of an inch toward the ends, it will enable the 
workman to lilt with it nearly twice as much hay as with 
one an inch and a quarter only through its whole length. 
A mode of adding strength to light bars of wo J 

means of braces, is shown in fig. 95, representing light 
.me-trees. stiffened by iron rods in a simple manner. 
The same method is sometimes adopted to advantage in 
making light fruit ladders, and for other purposes, 



CHAPTER VI. 
FEICTIOX. 



The subject of friction lias been postponed, or merely 

alluded to, to prevent the confusion of considering too 

many t *sat once. As it has an important influence on 

the action of machines, it is worthy of careful investigation. 

4* 



82 MECHANICS. 

It is familiar to most persons, that when two surfaces 
slide over each other while pressing together, the minute 
unevenness or roughness of their surfaces causes some ob- 
struction, and more or less force is required. This resist- 
ance is known as friction. 

ROLLING FRICTION. 

The term is also applied to the resistance of one body 
rolling over another. This may be observed in various 
degrees by rolling an ivory ball successively over a carpet, 
a smooth floor, and a sheet of ice ; the same force which 
would impel it only a few feet on the carpet would cause 
it to move as many yards on a bare floor, and a still 
greater distance on the ice. The two extremes may be 
seen by the force required to draw a carriage on a deep 
sandy or loose-gravel road, and on a rail-road. 

NATURE OF FRICTION. 

If two stiff bristle brushes be pressed with their faces 
together, they become mutually interlocked, so that it 
will be quite difficult to give them a sliding motion. This 
may be considered as an extreme case of friction, and 
serves to show its nature. In two pieces of coarse, rough 
sandstone, or of roughly-sawed wood, asperities interlock 
in the same way, but less in degree ; a diminished force is 
consequently required in moving the two surfaces against 
each other. On smoothly planed wood the friction is still 
less ; and on polished glass, where the unevenness can not 
be detected without the aid of a powerful magnifying 
glass, it is reduced still further in degree. 

ESTIMATING THE AMOUNT OF FRICTION. 

In order to determine the exact amount of friction be- 
tween different substances, the following simple and in- 



TO ASCERTAIN THE AMOUNT OF FRICTION. 83 

genious contrivance is adopted : An inclined plane, a b 
(fig. 96), is so formed that it may be raised to any desired 
height by means of the arc of a circle and a screw. Lay 
a flat surface of the substance we wish to examine upon 
this inclined plane, and another smaller piece or block of 
the same substance upon this surface ; then raise the plane 
until it becomes just steep enough for the block to slide 
down by its weight. Now, by measuring the degree of 
slope, we know at once the amount of friction. Suppose, 
for example, the two surfaces be smoothly-planed wood : 
it will be found that the plane must be elevated about 
half as high as its length ; therefore we know, by the 

Fig. 96. 




properties of the inclined plane, heretofore explained, that 
it requires a force equal to one-half the weight of the 
wooden block to slide it over a smooth wooden surface. 
Some kinds of wood have more friction than others, but 
this is about the average.* 

From the result of this experiment we may learn that 
to slide any object of wood across a floor requires an 
amount of strength equal to one-half the weight of the 
object. A heavy box, for instance, weighing two hundred 
pounds, can not be moved without a force equal to one 
hundred pounds. It also shows the impropriety of placing 



* These experiments may be made with tolerable accuracy, by hook- 
ing a spring-balance into any object of known weight, and then observ- 
ing the comparative force as measured by the balance, to draw it over a 
perfectly level surface. • - - : 



84 MECHANICS. 

a heavy load upon a sled in winter for crossing a bare 
wooden bridge or a dry barn floor, the friction between 
cast-iron sleigh-shoes and rough sanded plank being nearly 
equal to one-third of the whole weight.* Hence a load 
of one ton (including the sled) would require a draught 
equal to more than six hundred pounds, which is too much 
for an ordinary single team. On bare unfrozen ground the 
friction would be still greater. On a plank bridge, with 
runners wholly of wood, it would be equal to half the 
load. All these facts may be readily proved by actually 
placing the sled on slopes of plank and of earth, and by 
observing the degree of steepness required for sliding 
down by its own weight. 

In a similar way, we are enabled easily to ascertain the 
force required to draw a wagon upon any kind of level 
surface. Suppose, for example, that we wish to determine 
the precise amount of force for a wagon weighing, with 
its load, one ton, on a plank road. Select some slight de- 
scent, where the wagon will barely run with its own 
weight. Ascertain by a level just what the degree of de- 
scent is ; then divide the weight of the wagon by the de- 
gree of the slope, and we shall have the force sought for. 
To make this rule plainer by an example : It will be found 
that a good, newly-laid plank track, if it possess a de- 
scent of only one foot in fifty feet distance, will be suffi- 
cient to give motion to an easy-running Avagon ; therefore 
we know that the strength required to draw it on a level 
will be only one-fiftieth part of a ton, or forty pounds. 

The resistance offered to the motion of a wagon by a 
Macadam road, by a common dry road, and by one with 
six inches of mud, may be readily determined in the same 
way by selecting proper slopes for the experiment. If by 
such trials as these the farmer ascertains the fact that a 



* On clean hard wood, with polished metallic shoes, the friction 
"would be much less, or a fourth or fifth. 



EESULTS WITH THE DYNAMOMETEE. 85 

few inches of mud are sufficient to retard his wagon so 
much that it wiJl not run of its own weight down a slope 
of one foot in four (and few common roads are ever 
steeper), then he may know that a force equal to one-fourth 
the whole weight of his wagon and load will be required 
to draw it on a level over a similar road — that is, the 
enormous force of five hundred pounds will be needed for 
one ton, of which many wagons will constitute nearly one- 
half. Hence he can not fail to see the great importance, 
for the sake of economy, and humanity to his team, of 
providing roads, whether public or private, of the hardest 
and best materials. 

EESULTS WITH THE DYNAMOMETER. 

Another mode of determining the resistance of roads is 
by means of the Dynamometer* It resembles a spring- 
balance, and one end is fastened to the wagon and the 
other end connected with the horses. The force applied 
is measured on a graduated scale, in the same way that 
the weight of any substance is measured with the spring- 
balance. A more particular description of this instrument 
will be given hereafter. 

Careful experiments have been made with the dynamom- 
eter to ascertain accurately the resistance of various kinds 
of roads. The following are some of the results : 

On a new gravel road, a horse will draw eight times as 
much as the force applied ; that is, if he exerts a force 
equal to one hundred and twenty-five pounds, he will 
draw half a ton on such a road, including the weight of 
the wagon, the road being perfectly level. 

On a common road of sand and gravel, sixteen times as 
much, or one ton. 

On the best hard-earth road, twenty-five times as much, 
or one and a half tons. 



From two Greek words, dunamis, power, and metreo i to measure. 






86 MECHANICS. 

On a common broken-stone road, twenty-five to thirty- 
six times as much, or one and a half to two and a quarter 
tons. 

On the hest broken-stone road, fifty to sixty-seven times 
as much, or three to four tons. 

On a common plank-road, clean, fifty times as much, or 
three tons. 

On a common plank-road, covered thinly with sand or 
earth, thirty to thirty-five times as much, or about two 
tons. 

On the smoothest oak plank-road, seventy to one hund- 
red times as much, or four and a half to six tons. 

On a highly-finished stone track-way, one hundred and 
seventy times as much, or ten and a half tons. 

On the best rail-road, two hundred and eighty times as 
much, or seventeen and a half tons. 

The firmness of surface given to a broken-stone road by 
a paved foundation was found to lessen the resistance 
about one-third. 

On a broken-stone road it was found that a horse could 
draw only about two-thirds as much w r hen it was moist 
or dusty as when it was dry and smooth; and when 
muddy, not one-half as much. When the mud was thick, 
only about one quarter as much. 

The character of the vehicle has an influence on the 
draught. Thus, a cart, a part of the load of which is sup- 
ported by the horse, usually requires only about two-thirds 
the force of horizontal draught needed for wagons and 
carriages. On rough roads the resistance is slightly 
diminished by springs. 

On soft roads, as earth, sand, or gravel, the number of 
pounds draught is but little affected by the speed ; that is, 
the resistance is no greater in driving on a trot than on a 
walk ; but on hard roads it becomes greater as the velocity 
increases. Thus a carriage on a dry pavement requires 
one-half greater force when the horses are on a trot than 



WIDTH 0? WHEELS. 87 

on a walk ; but on a muddy road the difference between 
the two rates of speed is only about one-sixth. On a rail- 
road, where a draught of ten pounds will draw a ton ten 
miles an hour, the resistance increases so much at a hisfh 
degree of speed as to require a force of fifty pounds per 
ton at sixty miles an hour — that is, it would require five 
times as much actual power to draw a train one hundred 
miles at the latter rate as at the former ; but as the speed 
is six times as great, the actual force during a given time 
would be five times six, or thirty times as great. 

WIDTH OF WHEELS. 

Wheels with wide tire run more easily than narrow tire, 
on soft roads ; on hard, smooth roads, there is no sensible 
difference. Wide tire is most advantageous on gravel and 
new broken-stone roads, both by causing the vehicles to 
run more easily, and by improving the surface. For the 
latter reason, the New York turnpike law allows six-inch 
wheels to pass at half price, and twelve-inch wheels to pass 
free of toll. Wheels with broad tire on a farm would pass 
over clods, and not sink between them ; or would only 
press the surface of new meadows, without cutting the 
turf. But where the ground becomes muddy, the mud 
closes on both sides of the rim, and loads the wheels. On 
clayey soils, narrow tire unfits the roads for broad wheels. 
For these reasons, broad wheels are decidedly objection- 
able for clayey or soft soils, and they are chiefly to be 
recommended for broken-stone roads, and gravelly, or dry, 
sandy localities. They are also much better for the wheels 
of sowing or drilling machines, which only pass over 
mellowed surfaces. 

The larger the wheels are made, the more easily they 
run ; thus a wheel six feet in diameter meets with only 
half the resistance of a wheel three feet in diameter. 

A flat piece of wood, sliding on one of its broad sur- 



88 MECHANICS. 

faces, is subject to the same amount of friction as when 
sliding upon its edge. Hence the friction is the same, 
provided the pressure be the same, whether the surface be 
small or large.* Or, in other words, if the surfaces are 
the same, a double pressure produces a double amount of 
friction ; a triple pressure, a triple amount, and so on. 

A narrow sleigh-shoe usually runs with least force, for 
two reasons : first, its forward part cuts with less resist- 
ance through the snow ; and, secondly, less force is re- 
quired to pack the narrow track of snow beneath it. The 
only instance in which a wide sleigh-shoe would be best, is 
where a crust exists that would bear it up, and through 
which a narrow one would cut and sink down. 

VELOCITY. 

Friction is entirety independent of velocity ; that is, if 
a force of ten pounds is required to turn a carriage wheel, 
this force will be ten pounds, whether the carriage is 
driven one or five miles per hour. Of course, it will re- 
quire five times as much force to draw five miles per hour, 
because five times the distance is gone over ; but, measured 
by a dynamometer or spring-balance, the pressure would 
be the same. In precisely the same way, the weight of a 
stone remains the same, whether lifted slowly or quickly. 
If the friction of the wheels of a wagon on their axles be 
equal to ten pounds, driving the horse fast or slowly will 
not increase or diminish it. But fast driving will require 
more strength, for the same reason that a man would need 
more strength to carry a bag of wheat up two flights of 
stairs than one, in one minute of time. 

FRICTION AT THE AXLE. 

A carriage wheel, or any other wheel revolving on an 



* Generally speaking, this is very nearly correct ; but when the pres- 
sure is intense, the friction is slightly less on the smaller surface. 



SIZE OF WHEELS ON EOADS. 



89 



Fig. 97. 



axle, will run more easily as the axle is made smaller. 
This is not owing to the rubbing surfaces being less in 
size, as some mistakenly suppose, for it has just been 
shown that this makes very little or no difference, pro- 
vided the pressure is the same; but it is owing to the 
leverage of the wheel on the friction at the axis ; and the 
smaller the axle, the greater is this leverage ; for, if the 
axle, a (fig. 97), be six 
inches in circumference, 
and the wheel, b c, be 
ten feet in circumference, 
then the outer part of 
the wheel will move 
twenty times further 
than the part next the 
axle. Therefore, accord- 
ing to the rule of virtual 
velocities (already ex- 
plained,) one ounce of 
force at the rim of the 
wheel will overcome tAventy ounces of friction at the 
axle ; or if the axle were twice as large, then, according 
to the same rule, it would require two ounces to over- 
come the same friction acting between larger surfaces. 

For this reason, large wheels in wheel-work for multi- 
plying motion, if not made too heavy, run with less force 
than smaller ones, the power acting upon a larger lever. 
Horse-powers for thrashing-machines, consisting chiefly of 
a large, light crown-wheel, well stiffened by brace-work, 
have been found to run with remarkable ease; a good 
example of which exists in what is known as Talpirts 
horse-power, when made in the best manner. 




.....^Srarf**' 



FRICTION-WHEELS. 



On the preceding principle, friction-wheels or friction- 
rollers are constructed, for lessening as much as possible 



90 



MECHANICS. 



Fisr. 9S. 




Friction-ivheels. 



Ficr. 99. 



the friction of axles in certain cases. By this contrivance, 
the axle, a (fig. 98), instead of revolving in a simple hole 
or cavity, rests on or between the edges 
of two other wheels. As the axle re- 
volves, the edges turn with it, and the 
rubbing of surfaces is only at the axles 
of these two wheels. If, therefore, these 
axles be twenty times smaller than the wheels, the friction 
will be only one-twentieth the amount without them. 
This contrivance has 
been strongly recom- 
mended and con- 
siderably used for 
the cranks of grind- 
stones (fig. 99), but 
it was not found to 
answer the intended 
purpose so well as 
was expected, for 
the very plain reason 
that, in using a 
grindstone, nearly all the friction is at the circumference, 
or between the stone and the tool, which friction-wheels 
could not, of course, remove. 




Grindstone on Friction-wheels. 



LUBRICATING SUBSTANCES. 

Lubricating substances, as oil, lard, and tallow, applied 
to rubbing surfaces, greatly lessen the amount of friction, 
partly by filling the minute cavities, and partly by sepa- 
rating the surfaces. In ordinary cases, or where the 
machinery is simple, those substances are best for this 
purpose which keep their places best. Finely-powdered 
black-lead, mixed with lard, is for this reason better for 
greasing carriage wheels than some other applications. 
Drying oils, as linseed, soon become stiff by drying, and 



LUBRICATING SUBSTANCES. 91 

are of little service. Olive oil, on the contrary, and some 
animal oils, which scarcely dry at all, are generally pre- 
ferred. To obtain the full benefit of oil, the application 
must be frequent. 

According to the experiments made with great care by 
Morin, at Paris, the friction of wooden surfaces on wooden 
surfaces is from one quarter to one-half the force applied ; 
and the friction of metals on metals, one-fifth to one- 
seventh — varying in both cases with the kinds used. 
Wood on wood was diminished by lard to about one-fifth 
to one-seventh of what it was before ; and the friction of 
metal on metal was diminished to about half what it was 
before ; that is, the friction became about the same in both 
cases after the lard was applied. 

To lessen the friction of wooden surfaces, lard is better 
than tallow by about one-eighth or one-seventh; and tal- 
low is better than dry soap about as two is to one. For 
iron on wood, tallow is better than dry soap about as five 
is to two. For cast-iron on cast-iron, polished, the friction 
with the different lubricating substances is as follows : 

Water 31 

Soap ^ 

Tallow 



Lard. 



7 



Olive oil 6 

Laid and black-lead 5 

When bronze rubs on wrought iron, the friction with 
lard and black-lead is rather more than with tallow, and 
about one-fifth more than with olive oil. With steel on 
bronze, the friction with tallow and with olive oil is about 
one-seventh less than with lard and black-lead. 

As a general rule, there is least friction with lard when 
hard wood rubs on hard wood ; with oil, when metal rubs 
on wood, or metal on metal— being about the same in 
each of all these instances. 

In simple cases, as with carts and wagons, where the 



92 MECHANICS. 

friction at the axle is but a small portion of the resistance,* 
a slight variation in the effects in the lubricating sub- 
stance is of less importance than retaining its place. In 
more complex machinery, as horse-powers for thrashing- 
machines, friction becomes a large item, unless the parts 
are kept well lubricated with the best materials. 

Leather and hemp bands, when used on drums for 
wheel-work, should possess as much friction as possible, to 
prevent slipping, thus avoiding the necessity of tightening 
them so much as to increase the friction of the axles. 
Wood with a rough surface has one-half more friction 
than when worn smooth ; hence moistening and rasping 
small drums may be useful. Facing with buff leather or 
with coarse thick cloth also accomplishes a useful purpose. 
It often happens that wetting or oiling bands will prevent 
slipping, by keeping their surfaces soft, and causing them 
to fit more closely the rough surface of the drum. 

ADVANTAGES OF FRICTION. 

Although friction is often a serious inconvenience, or 
loss, in lessening the force of machines, there are many 
instances in which it performs important offices in nature 
and in works of art. " Were there no friction, all bodies 
on the surface of the earth would be clashing against each 
other; rivers would dash with an unbounded velocity, and 
we should see little besides collision and motion. At 
present, whenever a body acquires a great velocity, it soon 
loses it by friction against the surface of the earth. The 
friction of water against the surfaces it runs over soon 
reduces the rapid torrent to a gentle stream ; the fury of 



* If the friction at the axle be one-twelfth of the force, and the diam- 
eter of the wheels ten times as great as the diameter of the axle, the 
friction at the axles will be reduced to one-twelfth of a tenth, or one 
hundred and twentieth part of the force, according to the law of virtual 
velocities as applied to the wheel and axle. 



FRICTION NECESSARY TO EXISTENCE. 93 

the tempest is lessened by the friction of the air on the 
face of the earth, and the violence of the ocean is subdued 
by the attrition of its own waters. 

" Its offices in the works of art are equally important. 
Our garments owe their strength to friction, and the 
strength of ropes depends on the same cause ; for they are 
made of short fibres pressed together by twisting, causing 
a sufficient degree of friction to prevent the sliding of 
the fibres. Without friction, the short fibres of cotton 
could never have been made into such an infinite variety 
of forms as they have received from the hands of ingenious 
workmen." * Deprived of this retaining force, the parts 
of stone walls, piles of wood and lumber, and the loads 
of carts and wagons, as well as the wheels themselves, 
would slide without restraint, as if their surfaces were of 
the most icy smoothness, and walking without support 
would be impossible. 

The tractive power of locomotives depends on the fric- 
tion between the wheels and iron rails, which is equal to 
about one-fifth of the weight of the engine ; that is, a 
locomotive weighing twenty-five tons will draw with a 
force of five tons, without producing slipping of the 
wheels. 



CHAPTER VII. 



PRINCIPLES OF DRAUGHT. 



An examination of the nature or laws of friction enables 
us to ascertain the best line of draught for teams when 
attached to wagons and carriages. If there were no fric- 
tion whatever upon the road, the best direction for the 



* Encyclopaedia Americana. 



94 MECHANICS. 

traces would be parallel with its surface, that is, on a level ; 
but as there is always some friction, the line of draught 
should be a little rising, so as to tend to lessen the pressure 
of the wheels on the road. 

Now this upward direction of the draught should 
always be exactly of such a slope, that if the same slope 
were given to the road, the wagon would just descend by 
its weight. The more rough or muddy the road is, the 
steeper should be this line of draught or direction of the 
traces.* On a good common road it would be much less, 
and on a plank-road but slightly varied from a horizontal 
direction. On a rail-road the line should be about level. 
On good sleighing, some of the strength of the team is 
commonly lost by too steep a line of draught. 

The reason of this rule may be understood by the fol- 
lowing explanation : Let the obstruction, a, in the annexed 
Fi<>\ 100. figure (fig. 100) represent the friction the 

^ wheel constantly meets with in rolling 
over a common road. To overcome this 
"friction, the wheel must rise in the di- 
rection of the dotted line. Therefore, if 
a the force is made to pull in this direction, 
^fesSt^- fa w iu aC £ more advantageously than in 
any other, because this is the course in which the centre of 
the wheel must move. Now if a downward slope were 
given to the road at this obstruction, the wheel and the 
obstruction would both be brought on a level, and the 
wheel would move with the slightest degree of force. 

It will be understood from the preceding rule that a sled 
running on bare ground should be drawn by traces bearing 
upward in a large degree. The same remark will apply to 
the plow, which slides upon the ground in a similar way, 
with the pressure of the turning sod as a load. Hence 




* Provided the wheels are not made smaller for this purpose, increasing 
their resistance. 



PRINCIPLES OP DRAUGHT APPLIED TO PLOWS. 95 

the reason that a great saving of strength results from the 
use of short traces in plowing. An experiment was tried 
for the purpose of testing this reasoning ; first, with traces 
of such length that the horses' shoulders were about ten 
feet from the point of the plow ; and secondly, with the 
distance increased to about fifteen feet. With the short 
traces a strength was required equal to 2^ cwt., but with 
the long traces it amounted to 3^- cwt. 

But the draught-traces may be made too short. When 
this is the case, the Fi - 101 - 

plow is necessarily ~A" 

thrown too much upon ^=*^. ,*-'' \ 

its point, to keep it "~""^jp ^~~fl "" j 

from flying out of the >» g^^ -- — ' — i 

ground, by which means it works badly in turning the fur- 
row. In addition to this evil, the plowman is compelled to 
bear down heavily, adding to the friction of the sole on 
the bottom of the furrow, and greatly increasing his labor. 

The line of draught should be so adjusted that the plow 
may press equally all along on its sole or bottom, which 
will cause it to run evenly and with a steady motion. 

Fig. 102. 




Line of draujht for the plmv. 

This end will be effected by giving the traces or draught- 
chain just such a length that the share of the plow (or 
centre of resistance), the clevis, and the point of draught 
at the horses' shoulders (or the ring of the ox-yoke) shall 
all form a straight line. This is shown in the annexed 
figure, where A is the place of the ox-ring or of the for- 
ward extremity of the traces (fig. 101). 

The centre of resistance will vary with the depth of 



9G MECHANICS. 

plowing. When the furrow is shallow (as shown by the 
lines G H, fig. 102), the centre of resistance will be at A, 
requiring the team to be fastened to the lower side of the 
clevis, C ; but when the depth is greater (as shown by F 
H), the centre of resistance will be at B, requiring a 
higher attachment to the clevis ; the point of draught, E, 
remaining the same in both cases. 

So great is the difference between an awkward and skill- 
ful adjustment of the draught to the plow, that some 
workmen with a poor implement have succeeded better 
than others with the best; and plows of second quality 
have sometimes, for this reason, been preferred to those 
of the most perfect construction. 

COMBINED DRAUGHT OF ANIMALS. 

When several animals are combined together, it is of 
great importance that they should be exactly matched in 
gait. Much force is Fig. 103. 

often wasted when fc=qf= =$ 6= 
they draw unsteadily 
or unevenly. It is 
more difficult to di- 
vide the draught equally among several animals when 
placed one before the other, than when arrayed abreast, for 
some may hang back, and others do more than their share, 
unless a skillful driver is always on the watch. It also hap- 
pens, when thus arranged, that the forward horses draw hori- 
zontally, while the hindmost one draws in a sloping line, 
and the line of draught between them thus beincr crooked, 
more or less force is lost. This may be, however, remedied 
in part by placing the taller animals forward, and the 
smaller behind. 

For these reasons, when only three horses are used, they 
should always be placed abreast. The force required for 
each may be rendered exactly equal by the whiffle-trees 




COMBINED DRAUGHT OP ANIMALS. 



97 



usually employed for this purpose, and represented in fig. 
103, where two horses are attached to the shorter end, and 



Fisr. 104 





Whipplc-tree for three horses. 

the third to the longer end of the common bar. Another 
ingenious but more complex arrangement is shown by fig. 
104, where also the ,.. «_ B 

' Fig. 105. 

central horse has 
only half the two 
others, by being at- 
tached to the longer 
ends of the inter- 
mediate bars. An- 
other, and a more 
perfect contrivance, 
is Potters Three- 
horse Clevis, re- 
presented by fig. 105. It consists of two wheels to- 
gether, one twice the diameter of the other, and each 
having a groove in which a chain runs. The chains 
are fastened to the respective wheels, so that the 
single horse draws on the larger wheel, against the two 
horses on the smaller. With common whiflle-trees, the 
relative draught of each horse is maintained only when 
they draw evenly ; with Potter's there is no variation at 
any time. It is made by E. M. Potter, Kalamazoo, Mich. 
Fig. 108 represents the mode of attaching four horses in 
draught, their force being equalized by passing the chain 
round the wheel in the pulley-block, «, security being pro- 
vided that the hindmost pair shall not encroach on the 
5 



98 



MECHANICS. 
Fig. 106. 





forward pair, by connecting the end of the chain at the 
same time to the plow. 

wiee's single-teee. 

This is used exclusively for plowing in orchards, and is 
worthy of notice here. The leather traces are hooked at 
Fig. 107. the rear of the wooden 

bar, and, passing around 
the ends, prevent the 
possibility of being 
caught in the bark of the 
trees. The teamster may 
therefore drive as closely as he chooses without danger of 
injury. For this reason he is able to turn over the whole 
surface without leaving an unplowed strip along the row. 

CONSTEUCTION AND USE OF THE DYNAMOMETEE. 

The dynamometer, or force-measurer, has been already 
briefly alluded to, but a more particular description will 
be useful. In the construction and selection of all ma- 
chines and implements that require much power in their 
use, the dynamometer is indispensable, although at present 
but little known. As an example of its utility, the farmer 
may wish to choose between two plows which, so far as 
he can perceive, may do their work equally well ; but 
this instrument, when applied, may show that the team 



THE DYNAMOMETER. 



99 



must draw with a force equal to 400 pounds in mov- 
ing one of them through the soil, while 300 pounds would be 
sufficient for the other. He would, therefore, select the one 
of easiest draught, and by doing so would save the labor of 
one day in four to his team, or twenty-five days in a hund- 
red, which would be worth many times the cost of the 
trial. The same advantage might be derived in the selec- 
tion of harrows, cultivators, horse-rakes, straw-cutters, and 
all other implements drawn by horses or worked by men. 
Again, the farmer may be in doubt in choosing between 
two thrashing-machines, which in other respects may work 
equally fast and well ; but the dynamometer may show 
that one requires a severer exertion from the team, and 
consequently is less valuable for use. 

The operation of this instrument may be readily under- 




Dynamometer, or Force-measurer. 

stood by fig. 108, where b represents the dynamometer, 



Fi<?. 109. 




Elliptic Dynamometer. 

made precisely similar to a large and stiff spring balance, 



100 



MECHANICS. 



with one hook attached to the plow and the other to the 
whiffle-tree. The amount of force required to draw the plow 
is accurately measured on the scale by the index or pointer,^. 

Sometimes the motion of this index is multiplied, or 
made greater and more easily seen, by means of a cog- 
wheel and rack- work ; but this renders the instrument, at 
the same time, more complex. 

Another form of this instrument is shown in fig. 109, 

Ffff. no. 




Elliptic Dynamometer, in compact form : S S, spring; F, cross-lever for moving 

in.dcx. 

where the ends of the oval spring, Q Q, are attached to 
the plow and draught. The harder the force exerted by 
the team, the closer together will the sides of this spring 
be brought, causing the rod, E, to press against the index 
or pointer, and showing the precise degree of force on the 
circular scale. 

An improvement, by rendering the instrument more 
compact, is shown in fig. 110, where S S is the spring, and 
directly over it is the graduated scale. 



SELF-RECORDING DYNAMOMETER. 



101 



An inconvenience occurs in the use of the instruments 
now described from the rapid ! vibration of the index, re- 
sulting from the quick changes in the force, partly from 
inequalities in the soil, and partly from the unsteady mo- 
tion of the horses. The vibration is sometimes so great 
that the index can hardly be seen, rendering it difficult to 
measure the average force. This inconvenience has been 
removed, in a great degree, by attaching to one end of 
the index, E (fig. 110), a piston working in a cylinder filled 
with oil, C ; this piston has a small hole through it, through 
which the oil passes from one side to the other as the 
draught varies, but not fast enough to allow any sudden 
motion. 

SELF-RECORDING DYNAMOMETER. 



A less simple but more perfect instrument is the Self- 
recording Dynamometer, which marks accurately all the 

Fte. 111. 



-< — ^— -' 2fatio7i of /taper 


320 


*nn 




1 h 


260 




„.ii j Hi iii iili 


2G0 




klllilMillii 


840 


I " 




.I'!.: i:i|,!T./.T:!; 


220 


,11 Jili, II 




\ iii,j i |.,iJju |i 


200 




«l!l!l!l1IIH!lil l ii|il!iP 






180 




IHHI 






160 




j, i 






140 




■' i 






120 










100 










80 


1 






60 


J 






40 


j 






20 


i ■ ■ 

I 









The markings of the Self-recording Dynamometer. 

vibrations on a slip of paper while the plow is in opera- 
tion. A pencil is fixed to the index, and presses, by means 
of a spring, against the paper, thus giving a true register 




102 MECHANICS. 

of the force exerted. To prevent the pencil from con- 
stantly marking on the same line, the paper is made to 
move slowly in a side direction, so that all the vibrations 
are shown, as represented in fig. Ill, and they may be ac- 
curately examined and read off at leisure, a and b repre- 
senting the forces of two different plows, drawn through 
a single furrow across the field. The motion of the paper 
is effected by being placed on two rollers, one of which 
unwinds it from the other. This roller is made to turn by 
Fig. 112. means of a wheel running on 

the ground, which gives mo- 
tion to the roller through an 
endless chain, working a cog- 
wheel by means of an endless 
screw. The cylindrical dyn- 

Self -recording Dynamometer. amometer, shown ill fig. 112, 

is used for this purpose, lengthwise upon which the two 
rollers are placed for holding the paper. With this in- 
strument a permanent register might be made of the 
force required for different plows, with an accuracy not 
liable to dispute. 

waterman's dynamometer. 

All difficulties have been completely overcome by the 
recent invention of H. Waterman, of Hudson, N. Y. His 
dynamometer was used with entire success at the Auburn 
reaper trial in 1866, and at the trial of plows at Utica, in 
1867, under the Committee of the K. Y. State Agricul- 
tural Society. A full description of all the parts would 
require too much space for the character of this work ; the 
following is a brief explanation of the mode of its opera- 
tion: 

This dynamometer is furnished with a spiral spring, 
like those we have already described, working a piston in 
a cylinder of water. To this, two dial plates are added 



Fig. 113. 



waterman's dynamometer. 103 

one of which shows, by a slowly revolving index, the ex- 
act distance which the horses have traveled, without 
looking at in for a distance of more than five miles. 
The other dial plate gives a perfectly accurate record of 
the whole force expended from the commencement of the 
experiment to its termination. In other words, it takes 
all the different and varying forces, and adds them accu- 
rately in one aggregate or whole, seen at a glance on the 
dial plate under the eye. 

We shall attempt a brief description of the modes by 
which the indexes on these two dial plates are moved. 

The mode by which the distance traveled is recorded 
will be easily understood. A wheel one yard in circum- 
ference runs on the ground and communicates its 
motion by a cord, to a wheel attached to the dyna- 
mometer. This, by means of an endless screw 
and cog-work, moves the index slowly around the 
face, and thus records the distance traveled. There 
are two parts of this portion of the apparatus, which 
deserve a description. One is the wheel around 
which the cord passes in connection with the wheel 
which runs on the ground. It is very important that 
the exact number of the revolutions of this wheel should be 
maintained, as compared with those of the ground wheel. 
This is regulated as follows : The groove in this wheel is 
made by screwing together two beveled edged wheels, as 
shown in the annexed section, fig. 113. By placing thin pa- 
per between these two wheels, the width of the groove 
may be varied with the utmost accuracy, and the cord 
consequently let further in towards the centre. The other 
part wmich we desire to notice, although not original in 
this dynamometer, is the manner in which the index is car- 
ried around the face of the dial plate. There are two 
cog-wheels on the same axis, one with a hundred cogs, 
and the other with ninety-nine — both fitting into the same 
pinion. Consequently, when one has made the entire rev- 




104 



MECHANICS. 



olution, the other has fallen one cog behind, and a hund- 
red revolutions are required for the index, placed upon 
one of them, to come around again so as to coincide with 
its first position. 

The endless screw attached to the band- wheel already no- 
ticed moves one cog at every yard advanced, and the in- 
dex passing around in a hundred revolutions, it is obvious 
that it will show 10,000 yards, or more than five miles. 

We shall now attempt to describe that part of the ma- 
chine which furnishes an accurate record of the force. In 
doing this, we omit most of the details and vary some of 
the parts, in order to make the explanation simpler and 
clearer, the object being merely to explain the principle. 

The band- wheel a, fig. 114, (shown also in fig. 113,) re- 
volves once for every yard of onward movement, as already 
Fi 114 stated. In doing 

it causes the 




so, 
arm 



d 



c. to vi- 



brate backwards 
and forwards, on 
a pin at d ; the 
connecting; rod b 
c being set near 
the circumference 
of the wheel &, this vibrating movement is shown by the 
dotted lines at f and i. The slide h moves on this vibra- 
ting rod, by being connected with the spiral spring already 
described, which indicates the force of the draught ; the 
stronger the draught, the further this slide is moved toward 
c. When there is no draught at all, the rod e remains at 
the pivot d, and has no motion; but as the slide h 
is moved successively along the arm, this rod e is 
thrust backwards and forwards, more or less, accord- 
ing to the force of the draught. This thrusting move- 
ment turns the ratchet wheel g faster or slow T er as this 
force varies. A self-recording index is connected with 



waterman's dynamometer. 105 

this wheel by an arrangement similar to that already de- 
scribed for registering the distance. 

This explanation shows the principle of the self-regis- 
tering attachment, but in one respect it must be varied in 
order to be entirely accurate. The ratchet wheel must 
necessarily permit some play of the click or pawl, which 
would soon lead to serious error. This is wholly prevent- 
ed by facing the wheel with India rubber, and causing 
the pawls to press this India rubber surface. 

It will be observed that a movement of this wheel is 
made at every revolution of the band-wheel, or once in 
every yard ; and in traveling a hundred yards, a hundred 
such movements are made. Every one of these may be 
different in amount from the others, yet the whole sum 
will be accurately measured. 

It is absolutely essential that every part be finished with 
perfect workmanship, so that there may be no play or 
rattling of the teeth, producing loss of motion. Its 
measurements have been entirely satisfactory, although its 
records must necessarily vary with the condition of the 
cutting edge of plows, with the running order of mow- 
ing machines, the temper or sharpness of the knives, and 
the skill of the manager or driver. 

A more general use of the dynamometer would doubt- 
less result in important advantage to farmers as w T ell as 
plow-makers. The trials which have been made, both in 
this country and in Europe, have proved that a great dif- 
ference exists in plows, as to ease of draught, — some 
plows requiring a force more than fifty per cent greater 
than others, to turn a furrow of equal width and depth. 
Hence the farmer who employs the plow which runs most 
freely may accomplish as much by the use of two horses, 
as another can do by using one of hard draught by em- 
ploying three horses. 



k* 



106 



MECHANICS. 



DYNAMOMETER FOE ROTARY MOTION. 



All these dynamometers apply only to simple, onward 
draught, as in plowing, drawing wagons, harrowing, etc. 
There is another, represented in fig. 115, of very ingenious 
but complex construction, which shows the force required 
in working any rotary machine, such as thrashers, straw- 
cutters, and mills, and showing, at the same time, the ve- 
locity, and recording the number of revolutions made. 

The whole machine is supported by a cast-iron framer 

Fie. 115. 




Dynamometer for measuring the force and velocity of thrashing-machines. 

work, on four small wheels with flanges, like the wheels of 
rail-cars, that it may be conveniently run up on a temporary 
rail-way to the thrashing or other machine to be tried. 

The band-wheel /, on the shaft e, is connected with the 
machine under trial, and the force is supposed, in this in- 
stance, to be applied by hand to the handle a, on the fly- 
wheel. 



DYNAMOMETER FOR ROTARY MOTION. 107 

When the fly-wheel is turned in the direction shown by 
the arrow, it causes the two cog-wheels to revolve, and 
moves the band in the direction shown by the other arrow. 
JSTow, whatever force is required to turn the wheel f con- 
nected with the machine under trial, must be overcome by 
a corresponding force applied to the handle a, because 
the wheel-work is so adjusted that this handle moves with 
the same velocity as the band on the band-wheels. 

The wheel f being connected by the band to the wheel 
d, which is on the same axis or shaft as the cog-wheel /, 
the resistance of the machine under trial tends to keep 
the cog-wheel I from turning, until enough force is ap- 
plied to the handle a, to set the cog-wheel h in motion. 
Now the greater the resistance, the greater will be the 
power needed at the handle. This power, therefore, is 
measured accurately in the following manner : 

The axle g, of the cog-wheel I, rests at its further end 
in an oblong hole or mortise, which allows it liberty to play, 
or rattle up and down within narrow limits. This same 
axle, g, passes through a hole in the lever i so that when 
it rattles up and down, it carries this lever up and down 
with it. The other part of the lever turns on the shaft 
h of the other cog-wheel. 

Now when the man at the fly-wheel applies his force to 
the handle a, the resistance of the machine under trial 
causes the cog-wheel I to refuse to turn; consequently, 
his force, instead of turning it, lifts it up in the mortise, 
and raises the lever with it. As he increases his force 
against the handle, let weights be hang on the lever, until, 
at the very moment that the wheel begins to revolve, the 
weights shall be just heavy enough to keep the lever down' 
in the mortise. This weight, therefore, will measure the 
exact force needed to turn the machine : the greater the 
resistance of the machine, the greater must be the weight. 

There is another weight, J, used to balance the lever 
and cog-wheel I, while the machine is at rest, or before 



108 MECHANICS. 

the force is applied to it, so that the weight at m shall rep- 
resent the force truly. The weight m is, of course, to be 
multiplied by the power it exerts on the lever i, which 
should be graduated like the bar of a steelyard. 

There are a few other parts of this dynamometer not 
yet described. One is the cylinder o, filled with oil, in 
which a perforated piston works, preventing the rapid 
vibration of the lever », as the force varies, precisely 
similar to the cylinder of oil described in fig. 110, p. 100. 
Another part is the pendulum p, with the wheel r, which 
measures the time. 

The use of this instrument has been already attended 
with some important results in detecting the great amount 
of friction existing in some thrashing-machines of high 
reputation, which has been found to amount, in certain 
cases, to more than one-half of the whole power applied. 
It is only by detecting so great a waste that we are ena- 
bled to take measures for its prevention. 



CHAPTER VIII. 

APPLICATION OF LABOR. 

Most of the moving powers applied by the farmer to 
accomplish labor are the exertions of animal strength. A 
principal object of the preceding pages is to point out how 
this strength can be applied in the most economical 
manner, and to aid in the substitution of cheap horse- 
power for more costly human labor. It will doubtless 
contribute to the end to exhibit the relative efficiency of 
each, as well as the results of strength differently applied. 

The amount of work which any machine is capable of 
performing is denoted by comparing this amount with 



POWER OF HORSES. 109 

the power of a single horse ; hence the common expres- 
sions of twenty, or fifty, or a hundred horse-power 
engines. The strength of different horses varies greatly, 
but the expression, as commonly understood, indicates a 
force equivalent to raising or pressing with a force equal 
to 150 pounds 20 miles a day, at the rate of two and a 
half miles an hour. This is the same as 33,000 pounds 
raised one foot in one minute. The results of numerous 
experiments in different places give the actual power of 
the average of horses at somewhat less than this ; and 
there is no doubt that, for most of the farm-horses of this 
country, the result would be considerably less. The 
power of a strong English draught-horse has been ascer- 
tained to be about 143 pounds for 22 miles a day, at 2f 
miles an hour. Many American horses are scarcely more 
than half as strong. The strength of a man, working at 
the best advantage, is estimated at one-fifth that of a 
horse. 

As the speed of a horse increases, his strength of draught 
diminishes very rapidly, till at last he can move only his 
own weight. This is owing to three reasons : first, the 
load moves over a greater space in a given time, and if, 
for instance, the speed be doubled, half the load only can 
be carried with the same quantity of power, according to 
the law of virtual velocities ; secondly, the horse has to 
carry the full weight of his body, whatever his speed may 
be, and the force expended for this purpose alone must, 
therefore, be doubled as the speed is doubled ; thirdly, a 
very quick and unaccustomed motion of the muscles is in 
itself more fatiguing than the ordinary or natural velocity. 

The following table shows the amount of labor a horse 
of average strength is capable of performing in a day at 
different degrees of speed, on canals, rail-roads, and on 
turnpikes. The force of draught is estimated at about 83 
pounds. This is considerably less than the horse-power 
used in estimating the force of machinery, but it is as much 



110 MECHANICS. 

as an ordinary horse can exert without being improperly- 
fatigued with continued service : 



Velocity 
per hour. 


Duration of the 
day's work. 

Hours. 


Work accomplished for one day, 
one mile. 


in 


tons, drawn 


Miles. 


On a canal. 


On 


a rail-road. 


On 


a turnpike. 


2>li 


H 1 1 3 


520 




115 




U 


3 


8 


243 




9. 




12 


SMa 


5 9 | 10 


153 




82 




10 


4 


4^ 


102 




72 




9 


5 


2*1x0 


52 




57 




7.2 


6 


2 


. 30 




48 




6 


7 


1M 2 


19 




41 




5.1 


8 


l 1 Is 


12.8 




36 




4.5 


9 


3 Ik 


9 




32 




4 






10 sj 4 6.6 28.8 3.6 

From the preceding table it will be seen that a horse, at 
a moderate walk, will do more than four times as much 
work on a canal as on a rail-road ; but the resistance of 
the water increases as the square of the velocity, and 
therefore when the speed reaches five miles an hour, the 
rail-road has the advantage of the canal. On the rail- 
road and turnpike the resistance is about the same, 
whether the speed be great or little, the chief loss with 
fast driving resulting from the increased difficulty with 
which the horse carries forward his own body, which 
weighs from 800 to 1200 pounds. The table also shows 
that when it becomes necessary to drive rapidly with a 
load, it should be continued but for a very short space of 
time ; for a horse becomes as much fatigued in an hour, 
when drawing hard at ten miles an hour, as in twelve 
hours at two and a half miles an hour ; because when a 
boat is driven through the water, to double its velocity 
not only requires that twice the amount of water should 
be moved or displaced in a given time, but it must be 
moved with twice the velocity, thus requiring a four-fold 
force. 

The muscular formation of a horse is such that he will 
exert a considerably greater force when working horizon- 



POWER OP MEJf. Ill 

tally than up a steep, inclined plane. On a level, a horse 
is as strong as five men, but up a steep hill he is less strong 
than three; for three men, carrying each 100 pounds, will 
ascend faster than a horse with 300 pounds. Hence the 
obvious waste of power in placing horses on steeply 
inclined tread-wheels or aprons. The better mode is to 
allow them to exert their force more nearly horizontally, 
by being attached to a fixed portion of the machine. For 
the same reason, the common opinion is erroneous that a 
horse can draw with less fatigue on an undulating: than on 
a level road, by the alternations of ascent and descent 
calling different muscles into play, and relieving each in 
turn ; for the same muscles are alike exerted on a level 
and on an ascent, only in the latter case the fatigue is 
much greater than the counterbalancing relief. Any per- 
son may convince himself of the truth on* this subject by 
first using a loaded wheel-barrow or hand-cart for one day 
on a level, and for the next up and down a hill ; bearing 
in mind, at the same time, that the human body is better 
fitted for climbing and descending than that of a horse. 

A draught-horse can draw 1600 pounds 23 miles in a 
day, on a good common road, the weight of the carriage 
included. On the best plank-road he will draw more 
than twice as much. 

A man of ordinary strength exerts a force of 30 pounds 
for 10 hours a day, with a velocity of 2|- feet per second. 
He travels, without a load, on level ground, during 8^- 
hours a day, at the rate of 3.7 miles an hour, 31£ miles a 
day. He can carry 111 pounds 11 miles a day. He can 
carry in a wheel-barrow 150 pounds 10 miles a day. 

Well-constructed machines for saving human labor by 
means of horse-labor, when encumbered with little fric- 
tion, will be found to do about five times as much work 
for each horse as where the same work is performed by 
an equal number of men. For example : an active man 
will saw twice each stick of a cord of wood in a day. 



112 MECHANICS. 

Six horses, with a circular saw, driven by means of a good 
horse-power, will saw five times six, or thirty cords, work- 
ing the same length of time. In this case the loss by 
friction is about equal to the additional force required for 
attendance on the machine. 

Again : a man will cut with a cradle two acres of wheat 
in a day. A two-horse reaper should therefore cut, at the 
same rate, ten times two, or twenty acres. This has not 
yet been accomplished. We may hence infer that the 
machinery for reaping has been less perfected than for 
sawing wood. It should, however, be remembered, that 
great force is exerted, and for many hours in a day, in 
cutting wheat with a cradle, and therefore less than 
twenty acres a day may be regarded as the medium 
attainment of good reaping-machines when they shall 
become perfected. 

Applying the same mode of estimate, a horse-cultivator 
will do the work of five men with hoes, and a two-horse 
plow the work of ten men with spades. A horse-rake 
accomplishes more than five men, because human force is 
not strongly exerted with the hand-rake. 

In using different tools, the degree of force or pressure 
applied to them varies greatly with the mode in which the 
muscles are exerted. The following table gives the results 
of experiments with human strength, variously applied, 
for a short period : 

Force of the hands Force of the tool 

on the tool. on the object. 

With a drawing-knife 100 lbs. 100 lbs. 

" a large auger, both hands 100 " about 800 " 

" a screw-driver, one hand 84 " 250 " 

" a bench-vice handle 73 " about 1000 " 

" a windlass, with one hand 60 " 180 to 700 " 

" a hand-saw , 36 " 36 " 

" a brace-bit, revolving 16 " 150 to 700 " 

Twisting with thumb and fingers, but- 
ton-screw, or small screw-driver 14 " 14 to 70 " 

The force given in the last column will, of course, vary 



BEST WAY TO APPLY STRENGTH. 113 

with the degree of leverage applied ; for example, the 
arms of an auger, when of a given length, act with a 
greater increase of power with a small size than with a 
large one. This degree of power may be calculated for 
an auger of any size, by considering the arms as a lever, 
the centre screw the fulcrum, and the cutting-blade as the 
weight to be moved. The same mode of estimate will 
apply to the vice-handle, the windlass, and the brace-bit. 
Every one is aware that a heavy weight, as a pail of 
water, is easily lifted when the arm is extended downward, 
but with extreme difficulty when thrown out horizontally. 
In the latter case, the pail acts with a powerful leverage 
on the elbow and shoulder-joint. For this reason, all 
kinds of hand labor, with the arms pulling toward or 
pushing directly from the shoulders, are most easily per- 
formed, while a motion sidewise or at right angles to the 
arm is fat less effective. Hence great strength is applied 
in rowing a boat or in using a drawing-knife, and but little 
strength in turning a brace-bit or working a dasher-churn. 
Hence, too, the reason that, in turning a grindstone, the 
pulling and thrusting part of the motion is more powerful 
than that through the other parts of the revolution. 
This also explains why two men, working at right 
angles to each other on a windlass, can raise seventy 
pounds more easily than one man can raise thirty 
pounds alone. This principle should be well understood 
in the construction or selection of all kinds of machines 
for hand labor. 



CHAPTER IX. 

MODELS OF MACHINES. 



Serious errors might often be avoided, and sometimes 
gross impositions prevented, by understanding the differ- 
ence between the working of a mere model, on a miniature 



114 MECHANICS. 

scale, and the working of the full-sized machine. It is a 
common and mistaken opinion that a well-constructed 
model presents a perfect representation of the strength 
and mode of operation of the machine itself. 

When we enlarge the size of any thing, the strength of 
each part is increased according to the square of the 
diameter of that part ; that is, if the diameter is twice as 
great, then the strength will be four times as great ; if the 
diameter is increased three times, then the strength will 
be nine times, and so on. But the weight increases at a 
still greater rate than the strength, or according to the 
cube of the diameter. Thus, if the diameter be doubled 
(the shape being similar), the weight will be eight times 
greater ; if it be tripled, the weight will be twenty-seven 
times greater. Hence, the larger any part or machine is 
made, the less able it becomes to support the still greater 
increasing weight. If a model is made one-tenth the real 
size intended, then its different parts, when enlarged to 
full size, become one hundred times stronger, but they are 
a thousand times heavier, and so are all the weights or 
parts it has to sustain. All its parts would move ten 
times faster, which, added to their thousand-fold weight, 
would increase their inertia and momentum ten thousand 
times. For this reason, a model will often work perfectly 
when made on a small scale ; but when enlarged, the parts 
become so much heavier, and their momentum so vastly 
greater, from the longer sweep of motion, as to fail entirely 
of success, or to become soon racked to pieces. 

This same principle is illustrated in every part of the 
works of creation. The large species of spiders spin 
thicker webs, in comparison with their own diameter. 



i 



comparison 



than those spun by the smaller ones. Enlarge a gnat 
until its whole weight be equal to that of the eagle, and, 
great as that enlargement would be, its wing will scarcely 
have attained the thickness of writing-paper, and, instead 
of supporting the weight of the animal, would bend down 






WORKS OP CREATION FREE FROM MISTAKES. 115 

from its own weight. The larger spiders rarely have legs 
so slender in form as the smaller ones ; the form of the 
Shetland pony is quite different from that of the large 
cart-horse ; and the cart-horse has a slenderer form than 
the elephant. 

The common flea will leap two hundred times the length 
of its own body, and the remark has been sometimes made 
that a man equally agile, with his present size, Avould 
vault over the highest city-steeple, or across a river as 
wide as the Hudson at Albany. Now, if the flea were 
increased in size to that of a man, it would become a 
hundred thousand times stronger, but thirty million times 
heavier ; that is, its weight would become three hundred 
times greater than its corresponding strength. Hence we 
may infer that the enlarged flea would be no more agile 
than a man ; or that, if a man were proportionately 
reduced to the size of a flea, he could leap to as great a 
distance. 

All this serves to illustrate in a striking manner the 
great difference in the working of models and of machines. 



CHAPTER X. 

CONSTRUCTION AND USE OF FARM IMPLEMENTS AND MA- 
CHINES IMPLEMENTS FOR TILLAGE. 

The application of mechanical principles in the struc- 
ture of the simpler parts of implements and machines has 
been already treated of. It remains to examine more 
particularly those machines chiefly important to the farmer, 
and to show the application of these principles in their 
use and operation. 



116 MECHANICS. 

Farm implements and machines for working the soil 
should be, as far as possible, simple and not complex, be- 
cause they mostly meet with an irregular resistance, con- 
sisting of hard and soft soil and stones variously mixed 
together. A locomotive is made up of many parts ; but 
having a smooth surface to traverse, the machinery works 
uniformly and uninjured; but if in its progress it met 
with formidable obstructions and uneven resistance, it 
would be soon racked and beaten to pieces. Hence the 
long-continued and uniform success of the simple plow ; 
as well as the failure of complex digging machines, unless 
worked exclusively in soils free from stone. A complex 
machine, that meets with an occasional severe obstruction, 
receives a blow like that of a sledge ; and when this is 
repeated frequently, the probability is that some part will 
be bent, twisted, knocked out of place, or broken. If the 
machine be light, the chances are in its favor ; but il 
heavy, its momentum is such that it can scarcely escape 
severe injury. If composed of many distinct; parts, the 
derangement or breakage of one of these is sufficient to 
retard or put a stop to its working, and men and teams 
must stand idle till the mischief is repaired. 

Hence, after the trial of the multitude of implements 
and machines, we fall back on those of the most simple 
form, other things being equal. The crow-bar has been 
employed from time immemorial, and it will not be likely 
to go out of use in our day. For simplicity nothing ex- 
ceeds it. Spades, hoes, forks, etc., are of a similar char- 
acter. The plow, although made up of parts, becomes a 
single thing when all are bolted and screwed together. 
For this reason, with its moderate weight, it moves 
through the soil with little difficulty — turning aside from 
obstructions, on account of its wedge form, when it can- 
not remove them. The harrow, although composed of 
many pieces, becomes a fixed solid frame, moving on 
through the soil as a single piece. So with the simpler 






IMPORTANCE OF SIMPLICITY IX MACHINES. 117 

cultivators. Contrast these with the ditching machine 
(Pratt's) considerably used some years ago, but ending 
in entire failure. It was ingeniously constructed and 
well-made, and when new and every part uninjured, 
worked admirably in some soils. But it was made 
up of many parts, and weighed nearly half a ton. These 
two facts fixed its doom. A complex machine, weighing 
half a ton, moving three to five feet per second, could not 
strike a large stone without a formidable jar ; and con- 
tinued repetitions of such blows bent and deranged the 
working parts. After using a while, these bent portions 
retarded its working ; it must be frequently stopped, the 
horses become badly fatigued, and all the machines were 
finally thrown aside. This is a single example of what 
must always occur with the use of heavy complex machinery 
working in the soil. Mowing and reaping machines may 
seem to be exceptions. But mowers and reapers do not 
work in the soil or among stones ; but operate on a soft, 
uniform, slightly resisting substance, made of the small 
stems of plants. Every firmer knows what becomes of 
them when they are repeatedly driven against obstruc- ' 
tions by careless teamsters. 

There is another formidable objection to complex ma- 
chines — this is, their cost. Even with some of proved 
value, the expense is a serious item with moderate farm- 
ers. Mowers and reapers, $130; grain drills, $80 or $90; 
thrashing machines, $100 to $400 ; horse rakes, $45 ; hay 
tedders, $80 to $100 ; iron rollers, $50 to $100 ; and even 
some of the efficient new potato diggers are offered for 
not less than $100. Placing all these sums, and many 
others for necessary tools together, the whole will be 
found a large outlay — more economical by far, it is 
true, than doing without them; but greater simplicity 
and consequent cheapness, as well as durability, would 
facilitate progress in agricultural improvement. A single 
machine, Comstock's spader, is offered at $250 — twenty 



118 



MECHANICS. 



Fig. H6. 



times the price of the best cast-iron plow, and ten times 
that of the most finished steel plow. And yet it is ap- 
plicable only to land free from stone. 

The object of these remarks is to caution farmers against 
investing money in 
newly invented con- 
trivances of high 
promise at first, 
which are liable to 
the objection point- 
ed out ; and also in- Kool ° plow - 
ventors and manufacturers themselves against engaging in 
enterprises having at hand golden promises, but with 
failure in the distance. 




PLOWS. 

The simplest plow, used probably in the earlier ages of 
the world, and found at the present day only among de- 
graded nations, is the crooked limb of a tree, with a pro- 
jecting point for tearing the surface of the earth. The 
above figure represents an improvement on the first rude 
implement, and is found at the present day in Northern 

Fig. 117. 




Moorish Plow. 

India. Fig. 116 shows the Kooloo plow, consisting wholly 
of wood, except the iron point. Fig. 117 exhibits the 
implement now used in Morocco, which resembles the 
India plows, with the addition of a rude piece of tim- 
ber as a mould-board. Both these perform very imperfect 



PLOWS. 



119 



work, and have remained with little change for centuries, 
the owners not enjoying the benefit of agricultural read- 



rig. 118. 




ing and intelligence. Fig. 118 is a step in advance, and 
represents a plow still used in some parts of Europe. In 
the less improved portions of Germany, the Baden plow, 

Fig. na 




Pig. 120. 



Baden Plow. 
represented by Fig. 119, is employed, and does not differ 
greatly from the "bull plow" commonly used in this 
country at the beginning of the 
present century. Great im- 
provement has been made within 
the past fifty years, among others 
by the ingenuity and labors of 
Jethro Wood, and more recently 
by a great number of inventors 
and manufacturers in different 
parts of the country. Wood 
introduced the cast-iron plow 

. . , t n i Modern Improved Ploiv. 

into general and successiul use, 

by cheapening its construction and perfecting its form, 




120 



MECHANICS. 



and others have made important improvements, including 
the steel mould-board now largely employed at the West. 
Cast-iron plows have been generally used throughout 
the Eastern States ; but for the peculiar soil of the West, 
it has been found absolutely necessary to use steel plows 
exclusively ; and for the purpose of keeping them at all 

Fiff. 121. 




Moline Plow. 

times sharp for cutting the vegetable fibre and separating 
the parts of the soil readily, the practice is common to 
carry a large file or rasp for this purpose. These steel 
plows are made of plate previously rolled. They are be- 
coming partially introduced also at the East, although in 
hard and gravelly soils the cast-iron mould-board is pre- 
ferred by many, and Fig. 122. 
regarded as even 
more durable. The 
steel plate plow is 
lighter than the cast- 
iron, but is more 
expensive. The ac- 
companying figure Woodruff &, Allen's Steek-gkna. 
(Fig. 121,) represents the celebrated "Moline plow," made 
by Deere & Co., of Moline, 111., one of the best and most 
extensively introduced among the Western steel imple- 
ments ; and Fig. 122 shows an excellent one of Eastern 
manufacture, made by Woodruff, Allen & Co., of Auburn, 







CHARACTER OF A GOOD PLOW. 121 

N". Y. Good steel plows cost about double those made 
of cast-iron. 

CHARACTER OF A GOOD PLOW. 

Every good plow should possess two important quali- 
ties. The first relates to its working. It should be easily 
drawn through the soil, and run with uniform depth and 
steadiness. The second refers to the character of the work 
when completed. The inversion of the sod, especially if 
encumbered with vegetable growth, should be complete 
and perfect ; and the mass of earth thus inverted should 
be left as thoroughly pulverized as practicable, instead of 
being laid over in a solid, unmoved mass. This is of the 
greatest importance on heavy soils, and is highly useful 
on those of a lighter character, except, it may be, clear sand 
or the lightest gravels. The harrow, at best, is an imper- 
fect loosener ; it pulverizes the surface, but its weight, and 
that of the team, press down the mass below. Whatever 
loosening, therefore, can be accomplished in plowing is a 
gain of vital importance. 

THE CUTTING EDGE. 

The point and cutting edge of the plow perform the first 
work in separating the furrow-slice from the land. It is 
important that this edge should not only do the work well, 
but with the greatest possible ease to the team. The force 
required to perform this cutting is greater than many sup- 
pose. The gardener who thrusts his sharp spade into the 
hard earth uses more force than afterwards in lifting and 
inverting the spit. We may hence infer that a large part 
of the power of the team is expended in severing the fur- 
row-slice. This inference has been proved correct by the 
use of the dynamometer, in connection with carefully con-? 
(lucted experiments, which have shown the force usually 



122 



MECHANICS. 



expended for cutting off the side and bottom of the furrow- 
slice, in firm soils, to exceed all the rest of the force re- 
quired to draw the plow. The point or share should 
therefore be kept sharp, and form as acute an angle as 
practicable, as shown in Fig. 123. Some plows which other- 



Fig. 123. 



Fig. 124. 



Fig. 125. 






Fig. 126. 




wise work well arc hard to draw because the edge, being 
made too thick or obtuse, raises the earth abruptly. 
Fig. 124. 

Where stones or other obstructions exist in the soil, it is 
important that the line of the cutting edge form an acute 
angle with the land-side, or, 
in other words, that it form a 
sharp wedge, (Fig. 125.) It 
will then crowd these obstruc- 
tions aside, and pass them 
with greater ease than when formed more 
obtuse, as shown in Fig. 12G, for the same 
reason that a sharp boat moves more freely 
through the water than one which is blunt 
or obtuse. The gardener or ditcher proves 

this advantage when he thrusts a sharj> 
pointed shovel, Fig. 127, more easily through 
stony or gravelly soil, than one with a square 
edge. (Fig. 128.) 

But when the soil is free from stones, or 
obstructions, or is filled with small roots 
which the plow should cut off, as in the 
Western prairies, the sharpness of the edge 
is more important than its form ; and hence 
the reason that the use of the rasp or file becomes neces- 





THE CUTTING EDGE. 123 

saryin the field, to keep a sharp cutting edge at all times 
on the share. 

Note. — It has been shown in the Keport of the Trial of Plows at Utica, 
that so far as yet determined by experiment in England, about thirty-five 
per cent of the whole required draught is expended in overcoming the 
friction of the implement on its bottom and sides, about fifty-five for 
cutting the furrow-slice, and only about ten per cent for turning the 
sod. Hence the exclusive attention formerly given to forming the 
mould-board, as a means of reducing the draught, should have been 
directed more to lessening the force required for cutting the hard soil. 

These experiments, however, do not appear to have been entirely 
satisfactory, especially for the light plows of this country; and it may 
be interesting to test their accuracy by calculation. The average weight 
of hard earth is about 125 lbs. per cubic foot; and the average draught 
of plows at the trial near Albany in 1850 was about 400 lbs. for a furrow- 
slice a foot wide and six inches deep. If a team in turning such sod 
moves two miles an hour, it raises a slice three feet long, equal to a 
cubic foot and a half (weighing 187 lbs.,) six inches each second— which 
would be the same as raising 31 lbs. three feet per second, which is the 
velocity of the plow. The mere force required to turn the sod, not esti- 
mating friction, would therefore be only one-thirteenth of the 400 lbs. of 
draught force. But the friction of dry earth on smooth iron is never 
less than one-half its weight ; and if the earth is slightly plastic, its 
friction often is equal to, and sometimes exceeds, its weight. Taking 
the smallest amount, the friction on the mould-board would be equal to 
half the weight of the portion of sod resting on the mould-board, or 
about 31 lbs. This increased weight would also add equally to the fric- 
tion of the sole of the plow, or 31 lbs. more— making the whole friction 
62 lbs. ; which added to the weight of the sod would amount to 93 lbs. 
—or more than one-fifth of the whole draught. 

To ascertain the amount of friction, suppose the plow weighs 100 lbs. 
Half its weight would be 50 lbs., the friction on the sole of the plow. 
The friction of the sides would vary greatly with plows, being very 
small with those having a perfect centre-draught, or with no tendency 
to press against the land on the left. The whole friction and force for 
lifting the sod would therefore be about 150 lbs. ; leaving 250 lbs. as the 
force for cutting the slice. A very easy running plow would leave a 
much smaller force— some as low as 200 lbs. 

This estimate is liable to great variation. A wet and clayey soil would 
double the friction ; a very hard piece of ground would add much to 
the force required for cutting the slice ; if loose, the force would be com- 
paratively small; or if quite moist, this force would be also much dim- 
ished ; while the great difference in the draught of plows would vary the 
results still farther. The estimate, however, for soil dry enough to be 
friable, and of medium tenacity, is probably not far from correct, for 
plowing in this country— showing that most of the force required is for 



124 



MECHANICS. 



the act of cutting', and indicating the importance of giving special at- 
tention to the cutting edge. 

THE MOULD-BOARD. 

A prominent difference between good and bad plows 
results from the form of the mould-board. To un- 
derstand the best form, it must be observed that the slice 
is first cut by the forward edge of the plow, and then one 
side is gradually raised until it is turned completely over, 
or bottom side up. To do this, the mould-board must 
combine the two properties of the wedge and the screw. 

The position of the furrow-slice, from the time it is first 
cut until completely inverted, may be represented by 
placing a leather strap flat upon a table, and then, while 

Fiff. 129. 




holding one end, turning over the other, so as to bring 
that also flat upon the table, as in Fig. 129. 

Now, if the sole object were merely to invert the sod, 
the mould-board might have just such a shape as to fit 
the furrow-slice while in the act Fig. 130. 

of turning over, or resemble pre- 
cisely the twist of this leather strap. 
All the parts of this screw will be 
found to fit a straight-edge, if 
measured across at right angles, as indicated by the dot- 
ted lines in Fig. 130. 

But there are two objections to this form in practice. 
The first is that the sod is laid over smoothly and un- 
broken, and without being at all pulverized. On heavy and 
hard soils this is a serious fault. The other objection is 
that the sod is elevated as rapidly at the first movement, 
when its weight is considerable, as just before falling, 
when its pressure on the mould-board is slight. These diffi- 
culties are in part removed by giving the mould-board a 



THE MOULD-BOARD. 125 

shorter twist towards its rear. This form is distinctly 
shown in the figure of Holbrook's Stubble Plow, on 
a future page ; and it contributes largely to that crumbling 
movement of the sod, so important for effecting pulveriza- 
tion. 

The mould-board of a plow is capable of an almost infi- 
nite variety of forms, and the multitude of inventors have 
each adopted a different one. Some have made their 
selections by repeated random trials ; while others, among 
whom Thomas Jefferson was the first, devised a series of 
straight lines, mathematically arranged, by which uniform- 
ity was given to the shape. The limits of this work pre- 
clude a full explanation. Many modifications in com- 
bining lines have been adopted, the most successful of 
which is that of Ex-Governor Holbrook, of Vermont, 
whose plows made according to these rules have perform- 
ed admirably. It is less essential that farmers generally 
should understand these mathematical principles, provided 
they find a plow that will do good work ; because, as al- 
ready shown, the form of the mould-board has compara- 
tively little to do with the required draught of the team. 
Fi~ 1.31 ^ w *^ ^e rea dily understood, however, 

that more force will be needed for draw- 
ing a short or blunt ])low, like Fig. 131, 
than one in the form of a longer wedge, 
as in fig. 132, the latter, like a sharp 
boat in water, moving more easily. Care 
must be taken, however, that this slender wedge be not 
too long, else the friction of the sod on the extended sur- 
face may overbalance the advantage. Fi(r 133 
The cutting part of the plow may be 
improperly formed like the square end 
of a chisel, and the sod may slide back- 
ward on a rise, with a very slight turn, 
until elevated to a considerable height before inversion ; this 
must require more force of the team, and make the plow hard 





126 



MECHANICS. 



Fig. 133. 




to hold, on account of the side pressure. The character of 
this kind of plow may be quickly perceived by simply ex- 
amining the mould-board after use ; the scratches, instead 
of passing around horizontally, as they should do, are seen 
to shoot upward across the face and disappear at the top. 

Instead of this form, the point should be long and acute, 
and the mould-board so shaped as to begin to raise the 

left side of the sod 
the moment it is cut, 
and before the right 
side is yet reached 
by the cutting edge. 
This turning: motion 
being continued, the 
Ilolbroolc' s Stubble Plow, or Deep Tiller. S0( J j g inverted bv be- 

ing scarcely lifted from its bed ; and the pressure which 
turns it being opposite to the pressure of the land-side, an 
equilibrium of these two pressures is maintained, and the 
plowman is not compelled to bear constantly to the right 
to keep the plow in its place. 

There is, however, an exception, in deep or trench plow- 
ing, where it becomes necessary to throw the earth from 
the bottom of a furrow to the top of the inverted sod. A 
plow of this kind is represented in Fig. 133, which shows 
Holbrook's deep tiller for stubble land, capable of plowing 

a furrow a foot deep, and 
elevating the earth, which 
passes lengthwise over the 
mould-board. A similar 
Crested Furrow-dicer. f orm mus t be adopted for 

the rear mould-board of the Double Michigan Plow, so 
that the lower earth of the furrow may be thrown on 
the sod inverted by the first or skim-plow. 

The share should also be so placed as to cut the slice 
at equal thicknesses on both sides. Some plows are made 



Fi<r. 134. 




CRESTED FUItEOW SLICES. 



127 




so as to cut deepest on the land-side, forming a sort of saw- 
teeth section to the unmoved earth below, and leavino- 
what is termed crested or acute ridges at the top. (Fig. 
134.) Such plowing requires as much force in cutting the 
slice, and nearly Fig. 135. 

as much in turn- 
ing it over, as 
when level fur- 
rows are made, 
and should there- 
fore be avoided. 
The same result . 

is produced when ^ ie ^ rai 9^ Cutter, Laying Lapped Furrows. 

the plow is improperly gauged, and the plowman is com- 
pelled to press the handles to the left, to keep it from 
running too much to land. 

On heavy or clay soils, it is sometimes desirable to place 
inverted sod in an inclined or lapping position, in order to 
give more exposure to the crumbling action of the weath- 
er, and to effect better drainage beneath. Fig. 135 is a 
section of these lapped furrows. In order to be equally in- 
clined on both sides, their thickness must be precisely two- 
thirds their breadth ; that is, if the plow runs eight inches 
deep, the slices should be twelve 
inches wide. This mode of plow- 
ing is controlled by the position 
of the cutter, which should be 
very nearly upright, as shown in 
Fig. 135. It has been justly re- 
marked that the cutter to a plow 
(Fig. 136,) is almost as important 
as the rudder to a ship, and if 
its position be altered, as shown in The CuUer. 

Fig. 137, so as to cut under the sod, the furrows will cease 
to be lapped and will lie flat. This position is desirable 
in light or loose soils where exposure to the action of the 




128 



MECHANICS. 




air is not desirable, and where it becomes more important 

to bury com- 
pletely all veg- 
etable growth 
on the surface. 
If furrows are 
cut wider in 
proportion to 
their depth, 

The Inclined Cutter, Laying Flat Furroivs. they will be 

more likely to be laid flat. For example, if the plowing 
is six inches deep, and the furrows are a foot wide, the 
sod will generally dispose itself in a horizontal or flat 
position, and this result will be the more certainly secured 
by giving the form to the cutter already described. Lap- 
ping the furrows is the common practice in England, but 
is less necessary for this country, where the moisture of 
rains dries more quickly, and the severer frosts effect a 
ready pulverization ; and especially is the practice less 
needed in thoroughly drained land. 

The Committee for the trial of implements, appointed 
by the New York State Agricultural Society, enumerated 
the following desirable qualities in plows, which every 
farmer may find useful to examine when he is about to 
purchase. 1. Pulverizing power. 2. Non-liability to 
choke in stubble. 3. Lightness of draught, considered in 
connection with pulverizing juower. 4. Ease of holding. 
5. Durability. 6. Cheapness. 7. Excellence of mechani- 
cal work. 8. Excellence of material. 9. Thorough inver- 
sion and burial of weeds. 10. Even distribution of wear. 
11. Regularity or trueness of turning and carrying the 
furrow-slice in sod. 



OPERATION OF PLOWING. 



The expert plowman so adjusts his implement that it 
will cut a furrow r of just such width and thickness as 



OPERATION OF PLOWING. 129 

may be done with the least draught to the team, and the 
least exertion to himself. " To secure this end," says 
Todd, " the team is hitched as close to the plow as it can 
be and not have the whiffle-trees hit their heels in turn- 
ing at the corners. As the length of the traces is in- 
creased, in plowing, the draught increases. Now put the 
connecting ring, or link, or dial clevis, at the end of the 
beam, in the lowest notch ; and if it will not run deep 
enough, raise it another notch at a time until it will run 
just deep enough. Now alter the clevis from right to 
left, or from left to right, as may be necessary, until the 
plow will cut a furrow-slice just wide enough to turn it 
over well. If the plow crowds the furrow-slice without 
turning it over, it shows that the furrow-slice is too nar- 
row for its depth; and the plow must be adjusted to cut 
a wider slice. On the contrary, if the plowman is obliged 
to constantly push the furrow-slice over with his foot, if 
the ground he is plowing be very smooth and even, it 
shows that there is an imperfection or fault somewhere. 
Sometimes by adjusting a plow to run an inch deeper, it 
will do very bad work. And sometimes it is necessary to 
adjust it to cut a little wider, or a little narrower, before 
it will cut the furrow-slice as \\ r ell as it ought to be cut. 
When a good plow is correctly adjusted, it will glide 
along, where there are no obstructions, without being 
held, for many rods. When a j)low is constantly inclined 
to fall over either way, and the plowman must hold it up 
all the while, to keep it erect, there is either an imperfec- 
tion in the construction of the plow, or it is not adjusted 
correctly. When a plow " tips up behind" and does not 
keep down flat on its sole, or when it seems to run all on 
the point, either the point is too blunt, or is worn off too 
much on the under side, or there is not " dip enough " — 
pitching of the plow downwards — to the point. Some- 
times I have found that a plow could not be adjusted by 
the clevis so correctly as all the parts were arranged ; and 
6* 



130 MECHANICS. 

that by shortening the traces or draught chain, or giving 
them a little more length, it would run like another plow. 
When a plow is adjusted to run just right, as the point 
wears off it is necessary many times to give a little more 
length to the draught chains, or to adjust it with the 
clevis to run a little deeper. It is sometimes impossible 
to adjust a plow to run just right with the style of clevis 
which is on the end of the beam. The arrangement ought 
always to be such that the draught can be adjusted half 
an inch at a time, either up or down, or to the right or 
left. Then if the beam of the plow stands as it should, so 
that the most correct line of draught will cut the end of 
the beam, it can be most correctly adjusted in a few 
seconds. 

" To make a plow run deeper, raise the connecting point 
at the end of the beam one or more notches higher in the 
clevis; or lengthen the draught chains. To make it run 
more shallow, lower the draught a notch or more in the 
clevis ; or shorten the draught chains ; or, which should 
never be done, shorten the back-bands or hip-straps of the 
harness. To make a plow take a wider furrow-slice, carry 
the connecting point one or more notches in the clevis to 
the right hand. A notch or two to the left hand will 
make 'a plow cut a narrower furrow-slice. Or, which is 
seldom allowable, a plow may be made to run more shal- 
low by putting the gauge-wheel lower, so as to raise the 
end of the beam. And a plow may be made to cut a nar- 
rower furrow-slice by carrying the handles to the left 
hand, or wider by carrying and holding them to the right, 
beyond an erect position ; neither of which is allowable, 
except for a temporary purpose." 

PAST AND SLOW PLOWING. 

It has already been shown in the chapter on Friction, 
that the resistance is scarcely increased by velocity, when 
one body slides over another. The same rule, nearly, ap- 






FAST AND SLOW PLOWING. 131 

pears to apply to force required for cutting the earth, 
And as the friction of the plow and the force exerted in 
cutting the earth have been found to be the greater 
part of the whole draught, repeated experiments by the 
dynamometer have proved that but little increased resist- 
ance, as an average, occurs when a plow is drawn with in- 
creased velocity; the only additional power being that of 
doing more work in a given time. For example, if a force 
of 400 lbs. be required to draw a plow, whether at two or 
at four miles an hour, then twice as much power only is 
needed to plow an hour at four miles, as at two miles per 
hour. In other words, no more actual force in amount is 
necessary in most instances for a team to plow an acre in 
four hours at the faster speed than in eight hours at the 
slower. Hence the importance on the score of economy 
in time, of employing horses that have a naturally rapid 
gait, provided they possess full strength to overcome the 
required draught with ease. Fast plowing, however, is 
better adapted to stubble land than sod. 

THE DOUBLE MICHIGAN PLOW. 

The Double Michigan, called also the sod and subsoil 
plow, possesses some important advantages. The forward 
or skim plow pares oif a sod a few inches in thickness, 
and inverts it into the bottom of the previous furrow. 
The second or main plow follows, and throws up the lower 
soil, completely burying the inverted sod and giving a 
loose, mellow surface to the field. This forms an excellent 
preparation for all crops, particularly carrots and other 
roots, which grow best in a deep, loose bed of earth ; and 
where a portion of the subsoil improves the top-soil by be- 
ing mixed with it, a permanent advantage results. A 
greater depth may be attained by the use of this double 
plow than with one having a single mould-board, in sod 
ground, because the inversion will be complete even if the 




132 MECHANICS. 

width of the furrow is only one-half the depth. But with 
a single plow, the width must be considerably greater than 
the depth, or the Fio , 138 

sod will be thrown 
on its side or edge 
and cannot be in- 
verted. There is 

one disadvantage, 

Double Michigan Plow. 
however, m the 

use of the double plow. A greater force is required 
to make two cuts in the soil, one above the other, than 
one cut with a single share.* For this reason more 
force must be used to plow a field to a given depth, say 
one foot, with the double than with the single plow. But 
the single plow, in order to reach this depth, would re- 
quire to be so large and to turn so wide a furrow that no 
ordinary amount of team could be had to do the work. 
And in addition to this difficulty the inverted surface would 
not be so well pulverized as by the use of the double 
plow. 

THE SIDE-HILL PLOW. 

Side-hill or Swivel plows are well known, and are so 
constructed as to throw the furrow-slice down hill, which- 
ever way the team may be passing. The mould-board is 
turned to the right and left alternately for this purpose, 
the right-hand horse walking in the furrow in one direc- 
tion, and the left-hand horse in the other. This plow is 
sometimes used for level land when it becomes desirable 
to avoid dead furrows and ridges, "without plowing around 
the field. Fig. 139 represents the swivel plow manufac- 

* This result lias been proved by the use of the dyuamometer ; which 
has also shown that a greater amount of earth, in cubic feet, may be 
turned over with a deep-running plow than with a shallow one, as there 
is less force expended in cutting the slice when compared with the whole 
bulk — provided the soil is nearly uniform in hardness at different depths. 



THE SIDE-HILL PLOW. 



133 



Fig. 139. 
Holbrook's Patent Swivel Plow. 




tured by F. F. Holbrook & Co., Boston, one of the best 
in use, and particu- 
larly valuable for its 
thorough pulveriza- 
tion of the soil. One- 
half of the double 
mould-board shown 
in the cut is used for 
throwing the flllTOW Holbrookes Stvivel or Side-hUl Plow. 

to the right, and the other half to the left — the change 
being effected by passing it under the plow with a single 
movement and hooking it in place. 

THE SUBSOIL PLOW. 

When the common two-horse plow alone is used by 
farmers, it pulverizes the soil only a few inches in depth, 

Fi<?. 140. 




Subsoil plowing in the furrow of a common plow. 

and its own weight and the tread of the horses on the 
bottom of the furrow gradually form a hard crust at that 
depth, through which the roots of plants and the moisture 
of rains do not easily penetrate. Hence the roots have 
only a few inches of good soil on the surface of the earth 
for their support and nourishment ; and when heavy rains 
fall, the shallow bed of mellow earth is soaked and injured 
by surplus water. Again, in time of drought, this shal- 
low bed of moisture is soon evaporated, and the plants 
suffer in consequence. 

But, on the other hand, when the soil is made deep, it 
absorbs, like a sponge, all the rains that fall, and gradually 
gives off the moisture as it is wanted during hot and dry 
seasons. For this reason, deep soils are not so easily in- 



J 34 MECHANICS. 

jured by excessive wetness, or by extreme drought, as 
shallow ones. In addition to this advantage, they allow 
a deeper range for the roots in search of nourishment. 

Soils are deepened by trench-plowing and by subsoiling. 
In trench-plowing, the common plow with a mould-board 
is made to enter the earth to an unusual depth, and to 
throw up a portion of the subsoil, covering with it the 
top-soil which is thrown under. A subsoil plow, on the 
contrary, only loosens the subsoil, but does not lift it to 
the surface. 

The Double Michigan Plow, just described, is strictly a 
trench-plow, and is one of the best implements for this 
purpose. 

When the subsoil is of such a character that its mixture 
with the surface tends to render the whole richer, trench- 
plowing is best ; but when of a more sterile character, it 
should be only loosened with the subsoil plow, and more 
cautiously intermixed with the richer portion above. 

It often happens that the subsoil plow is very useful in 
loosening the soil for the purpose of allowing the trench- 
plow to run more freely through it. 

The operation of the subsoil plow is shown in fig. 140. 

In using the subsoil plow the less the earth is raised, 
provided it is well broken to pieces, the easier will be the 
draught. The part which moves under the soil and per- 
forms this loosening is of course in the form of a wedge. 
If the subsoil is dry, hard, and not adhesive, a long and 
acute wedge will run most easily ; but if the subsoil is 
stony, a shorter wedge will succeed better. For general 
purposes it should therefore be of medium length. 

Different modes of connecting this wedge to the beam 
above have been adopted, each possessing its peculiar ad- 
vantages. Fig. 141 represents a subsoil plow with a 
single, broad, upright shank, cutting like a wedge, with 



THE SUBSOIL TLOW 



135 






double edges as well as double points, and capable of be- 
Fi »- 141 - ing reversed when 

it becomes worn. 
In light or grav- 
elly soils this plow 
runs well ; but 
where the earth 
adhesive and 




is 



Broad-shank SubsoUer. 



rather moist, the 
friction of the two faces of this shank in pressing the 

Fig. 142. 




-iC=«x^. 



Subsoil plow. 



compact soil apart becomes enormous, amounting in some 

cases to more than triple the force required to loosen 

Fig. 143. the soil below. 

This plow is there- 
fore not to be rec- 
ommended for 
general use. The 
objection is in a 
great measure ob- 
viated in the plow 
shown in fig. 142, 
where the forward portion of the broad plate is made 
thicker than the rest. The friction is still further less- 
ened by employing two narrow shanks, as in fig. 143, 

Another improvement for lessening friction might be 
made by using narrow bars of iron or steel, braced and 




Two-shanked Subsoiler. 



136 



MECHANICS. 



Fig. 144. 




connected as shown in fig. 144. The ditching plow, 
exhibited in fig. 147, is similar in the construction of 

this part, and it 
has been found 
to work well 
for subsoiling, 
particularly in 
stony land. If 
the subsoil hap- 

Brace-sJiank Subsoiler. pens to be filled 

with roots, the interstices in these plows sometimes become 
choked — a difficulty, however, which rarely occurs. In 
such cases it may be better to employ the plow represented 
by fig. 141. 

New subsoil plows have been lately constructed at the 
West, by which the operations of both plows are perform- 
ed at once. A saving is thus made in the expense of the 
implement and in the labor of one man. In one, known 
as the Nichols' plow, a flat, triangular blade runs a few 
inches below the common plow; in Wheatley's, a narrow 
blade bent like the letter U beneath the plow performs 
the work. 

The benefit of subsoiling will last three or four years ; 
but it is of great importance that land be well under- 
drained, for if the earth becomes heavily soaked with wa- 
ter, it settles down into one compact mass, and the advant- 
ages of the operation are lost. 

THE TAKING PLOW 

consists merely of a flat blade, which runs beneath the 
surface, shaving off the roots, but not moving the soil (fig. 
145). A shield, shown in the cut, is placed beneath the 
beam, to regulate the depth of the cutting blade. It is 
used in cutting turf for burning, and for destroying this- 
tles and other deep-rooted weeds. When made light for 
a single horse, it is sometimes used advantageously for 



THE GANG PLOW. 



13? 



cutting the grass and weeds between rows of badly tilled 
corn. A two-horse paring plow has been constructed, in 
which the depth of cutting is accurately regulated by 
wheels placed on an axle, like those of a cart. The cast- 

Fisr. 145. 




^tsisz^Wi-UUVt*" 



Paring plow. 

iron blade, which cuts about three feet wide, is raised or 
depressed by means of screws passing through the axle. 
Its chief utility is in destroying grass and weeds before 
the sowing of broadcast crops. 



THE GANG PLOW 

consists of three or four small mould-boards placed side 
by side (fig. 146), and is used for shallow plowing, or for 

Fi<r. 14G. 




Gang plow. 

burying manure or seed on inverted sod, without disturb- 



138 M'ECHAmCS. 

ins; the turf beneath. In those of the best construction, 
the depth is regulated by wheels, and the breadth of the 
furrows by turning the cross-beam more or less obliquely, 
by means of a fixed contrivance for this purpose. The 
gang plow is liable to become impeded or clogged by 
stubble, coarse manure, or weeds, and has not come into 
extensive use. 

DITCHING PLOWS. 

In most localities where tile drains are made, two-thirds 
of the labor of cutting is loosening the earth with the 
pick, before shoveling it out. By means of the ditching 
plow this laborious work is performed by horses. One 
span, with a good plow made for this purpose, will loosen 
the subsoil fast enough for eight or ten men shoveling, 
and cutting about 100 rods 3 ft. deep in a day ; or an hour 
M „ . or two each day with 

Fig. 147. / 

efSSS ^ the plow will keep 

..<y^^Z^=^ ^ w0 men a ^ wor ^« 

^""^^'ifr--^- J^^^^*^ ^ tne su ^ sou i s very 

gj^ _ - t ^zL 1 ^--'' "t ^ SSST p hard, this work 

/((K ^jKjr i'J should be done early 

^^ Jni Wsi^ ^ n summer. The 

implement is drawn 
by two horses, at- 
tached to the ends of a main whiffle-tree about seven feet 
long, one walking on each side of the ditch. From one 
to three times passing will loosen the subsoil five to eight 
inches, which is then thrown out by narrow shovels, on 
both sides, so that it may be easily returned after the tile 
is laid, by means of a common plow drawn by the long 
whime-tree before mentioned. 

There are several modifications of the ditching plow, all 
accomplishing the same end. The adjustable ditching 
ploio, (fig. 147,) admits of so great a change in the height 



Adjustable Ditching rioic. 



DITCHING PLOWS. 139 

of the beam and handles, that it may be run down in the 
bottom of a ditch to a depth of four feet. It is, perhaps, 
the best implement of the kind for all purposes and soils. 
The movable portion of the beam is attached to the fixed 
beam by a stout loop and staple, and rises on a cast-iron 
arc, which passes through it, as shown by the dotted lines. 
The handles rise on a stiff, wooden arc, (as the dotted lines 
exhibit,) a piece of thick plank, shown in the small figure 
on the right, being placed between the handles and fast- 
ened to them, to render them more firm and steady. The 
iron work, although light, is braced so as to impart great 
strength and security. The point is screwed on separate- 
ly, and is nearly the only part that wears by use. 

This ditching plow may be used for common subsoiling, 
the shortness of the share rendering it especially adapted 
to stony land. 

Several ditching machines have been constructed for 
performing the entire operation of cutting the earth and 
throwing it out, but nearly all of them are too complex 
for common use. Except in land entirely free from stone, 
some of their many parts are liable to become bent or in- 
jured by use, and a very slight derangement of this kind 
renders them partly or entirely useless. Any ditching 
machine, therefore, to work well among stone, must be 
simple and strong, so as to withstand the frequent shocks 
met with in overcoming obstructions in the soil. 

MOLE PLOW. 

The Mole Plow has a wooden beam, sheathed with iron 
on the lower side, which moves close to the ground, be- 
low which a thin, broad coulter extends downward, and 
to the lower end of this coulter a sharp iron cylinder is 
attached. This moves horizontally, point foremost, through 
the soil, producing a hollow channel beneath the plow for 
the escape of the water, the only trace on the surface be- 



140 MECHANICS. 

ing a narrow slit left by the coulter. It is dragged for- 
ward by means of a chain and capstan worked by a horse, 
the machine itself being fixed with strong iron anchors. 
This mode of draining is only adapted to clay soil, free 
from stone, and although cheaply performed, has been little 
used since the introduction of tile-draining. 

APPENDAGES TO THE PLOW. 

Wheel Coulters. — In soils free from stones and coarse 
gravel, and especially on the Western prairies, wheel 
coulters are found to answer a good purpose, cutting 
through the turf and roots of grass with great ease, and 
making a smoother slice than the common cutter. But 
where stones and other obstructions exist, it is necessary 
to use the simpler, single blade coulter. A good repre- 
sentation of the wheel coulter is seen on the figure of the 
Moline Plow, on an early page of this chapter. 

Weed-Hook axd Chaix. — In turning under large 
weeds, grass, or other tall vegetable growth, two modes 
are adopted. One is Fig. i^s. 

the use of the weed 
hook represented in 
the annexed cut ; 
and the other is that 
of a chain. The 
weed-hook has been 
long known, and is 
made in various Weed-hook. 

forms. Sometimes it is bent in the form of a bow 
with the lower point projecting forward, as in the upper 
figure ; another form is like that shown in the lower cut, 
pointing backwards. This is less liable to be caught by 
obstructions. The weed-hook operates on the principle 
of bending the tall growth forward and prostrate, so that 
the turning sod completely buries it. The same object is 




WEED-HOOK AND CHAIN. 141 

attained by the use of a heavy chain ; and different modes 
are used for attaching it to the plow. One of the sim- 
plest is to fasten one end to the right-hand portion of the 
main whiffle-tree, and the other to the right handle. In 
another mode, the chain forms a loop. All these modes 
of burying vegetable growth are important in turning 
under clover and other green crops. 

The weed-hook is usually made of round rod-iron, stiff 
enough to perform its work, and to possess some spring 
when it meets with obstructions. Those not accustomed 
to its use may adjust its position by bending it, until it 
performs satisfactorily. It is secured to the plow-beam 
by placing the forward end in a small groove cut length- 
wise in the under side of the beam, passing a band over 
it, and wedging until properly secured. Lighter and more 
perfect weed-hooks may be made of steel rod, similar to 
that used for rake teeth ; they will bend back on meet- 
ing obstructions, and spring again into position. Such 
weed-hooks should be made and sold with the other ap- 
pendages of plows, now that the inversion of green clover 
for manure has become an essential part of good farming. 
Sometimes the weed-hook is made to extend at right 
angles to the plow-beam, curving outwards and down- 
wards. This form requires greater stiffness, and small bar- 
iron is used. 

No plow will cover weeds or other growth two or three 
feet high ; but by the use of this hook, the whole is laid 
completely under the surface. 

Regulating Wheel. — It has long been a question witli 
plow men whether the wheel under the beam for regula- 
ting depth is really a disadvantage or a benefit. It is fully 
shown in the able Report by J. Stanton Gould, of the Trial 
of Plows at Utica, drawn from accurate experiments, that 
the wheel not only gives better plowing with moderate 
skill, but that it slightly lessens the draught. Uniformity 
in the depth of the slice is preserved, without constant 



142 MECHANICS. 

vigilance on the part of the attendant ; and this uniform- 
ity, by preventing uneven running, lessens the aggregate 
amount of draught. It is, however, quite important that 
the wheel sustain little or no pressure ; for as soon as the 
beam bears upon it, the line of draught becomes crooked 
at the expense of the team. These facts were established 
by careful experiments with the dynamometer. 

PULVERIZERS. 

The fine pulverization of the earth, for the ready ex- 
tension of the roots of plants, for the action of air on the 
soil, for the retention of moisture, and for the thorough in- 
termixture of manure, is of great importance to the fanner. 
It is but partially accomplished by the plow, which crum- 
bles the soil only so far as may be done by the act of 
turning it over. Hence additional implements are needed 
for this purpose, among which are the harrow, the cultiva- 
tor, and the clod-crusher. 

HARROWS. 

The JBrush-harroic, the original and rudest form of the 
implement, and still used for covering grass seed, as often 
made, is a poor implement. The 
most projecting limbs are cut partly 
off, that all may lie flat, but it often 
happens that the projecting angles of 
the larger branches plow into the 
around and make deep furrows. This 

Brush-harrow. n , , n . . 

may be prevented by a caretul selec- 
tion of the small tree which forms the brush, or still better 
by constructing a simple rough plank frame, so that any 
quantity of short brush may be placed between two pieces 
of plank, to admit the tops of the brush to incline down- 
wards and backwards, being held in place by a few spikes 
or bolts. Fiff. 149. 




GEDDES AND SCOTCH HARROWS. 



143 




Geddes Harrow. 



The Geddes Harrow is one of the best in use for rough or 
uneven land. The teeth being situated considerably back 
of the point of draught, its motion is even and steady, 

and easy for the team. In conse- 
quence of its wedge-form, it passes 
obstructions more readily. The 
center or draught-rod forms a set 
of hinges, by which it becomes 
adapted to uneven ground, or by 
which it may be easily lifted to 
discharge weeds, roots, or other 
obstructions. Or it may be doubled 
back, and carried easily in a wagon. 
The accompanying figure (fig. 150) 
renders its construction intelligible, 
without further description. To jjrevent its 
rising in the middle, as it has been found to do 
when the draught traces are as short as easy 
draught requires, the chain is attached to the 
bar on each side, as shown in fig. 151. Ml 

The Square Harrow admits of a larger number of teeth, 
and when made in the best form, effects thorough pulveri- 
zation on smooth land, free from obstructions. A modifi- 
cation known as the Scotch Fig. 152. 
harrow, represented in fig. 
152, has forty teeth, inserted 
in such a manner that each 
tooth forms a separate track, 
? as shown by the dotted lines. 
The hinges, as 111 all square 
harrows, enable it to fit a 
rolling or uneven surface, 
and it may be folded for 
carrying in a cart or wagon. Scotch or S( i uare harrow. 
For the fine pulverization of a smooth surface, a still 
greater number of teeth has been found to answer an 





144 



MECHANICS. 



excellent purpose, leaving the soil almost as smooth as a 
garden bed. Tough and sound timber, only two inches 
square, is used for the frame, and the teeth are five- 
eighths of an inch square. 

The Morgan Harrow is an improvement of the Scotch 
implement, slots being made in the hinges, so that each of 
the two portions is capable of playing freely up and 
down, as the surface varies, and rendering the rear teeth 
less liable to follow in the track of the preceding. The 
draught-iron is made to slide on an iron arc, so that the 
lines formed by the teeth are controlled at pleasure. It 
is converted into a broadcast cultivator by inserting flat 
teeth, the flat portion below being the same in width as 
above, and pointing slightly forwards. These teeth pul- 
verize the soil deeply and thoroughly. They are success- 
fully used for digging potatoes, operating like a large 
number of potato-hooks, drawn by horses. 

The Norwegian Harrow (fig. 153) is a new machine for 

Fiff. 153. 




Norwegian Harrow, kept from clogging by two cylinders of teeth 
playing into each other. 

pulverizing the soil, which performs the work in a very 
perfect manner, by turning up, instead of packing down, 
the earth. Two rows of star-shaped tines play into each 
other, and produce a complete self-cleaning action, pre- 
venting clogging even in quite adhesive soils. Its com- 



SHARES HARROW. 



145 






Fi£.154. 



plex character and cost have prevented its coming into 
more general use. 

Shares' Marrow (fig. 154) is the most perfect of all im- 
plements for pulverizing the freshly inverted surface of 
sward land, to a depth two or three times as great as the 
common harrow can effect. The teeth being sharp, flat 

blades, cut with great ef- 
ficiency ; and as they slope 
like a sled-runner, they pass 
% over the sod, and instead of 
tearing it up like the com- 
mon harrow or gang-plow, 
they tend to keep it down, 
and in its place, while the upper surface of the sod is 
sliced up and torn into a fine, mellow soil. The price of 
Shares' harrow is about $20, but if furnished with steel 
teeth, as it should be, it would cost more. 

CULTIVATORS. 




Shares' Harroio. 



The Cultivator or Horse-hoe is used for loosening and 
pulverizing the soil among drilled crops, and for cutting 
and destroying weeds. A usual form is shown in fig. 155, 
which represents 
Holbrook's, one 
of the best of its 
kind. The wheel 
in front regulates 
the depth ; the 
sides may be ex- 
panded or con- 
tracted sufficient- 
ly to vary the 
width from fifteen to thirty-six inches ; they are reversible, 
so that the soil may be thrown from or towards the row ; 
and the frame is high enough to prevent clqgging witfr 
7 




Holbrook's Horse-hoe or Cultivator. 



146 MECHANICS. 

weeds, stubble, or manure. Various forms of teeth are 
used, according to the nature of the work, and they are 
made of steel or cast-iron. The steel teeth, represented 
in fig. 152, are well adapted for cultivating the rows of 
Indian corn and other hoed crops, where the soil is al- 

Fig. 150. 




Claw-toothed cultivator for hard ground. 

ready moderately mellow. For harder soils, the teeth 
should be in the form of claws, as shown in fig. 156, their 
sharp, wedge-form points penetrating and loosening the 
earth with comparative ease. An efficient cultivator is 
made by using both kinds of teeth in the same implement, 
placing the claws forward for breaking the hard earth, and 
the broader teeth behind for stirring it. 

Steel plates, with sharp or " duck-feet " edges screwed 
at the lower ex- Fig. 157. 

tremities of the 
teeth, (fig. 157) 
are useful for par- 
ing or cutting the 
roots of weeds; 
and formed like 
the mould-board of a plow, they are used for throwing the 
mellow earth toward the row, or, when reversed, from it. 

Aiders Thill Cultivator is furnished with fixed thills, 
extending backwards from the handles. The whole im- 
plement thus runs with remarkable steadiness and great 
efficiency, and the driver, by bearing on the handles, 




GAKRETt's HORSE-HOE. 



147 



readily increases the depth of the teeth, or by bearing to 
the right or left, guides it in the row. It is not capable 
of being expanded and contracted in width. 

Garretfs Horse-hoe, an English invention, is a modifi- 
cation of the cultivator, and is used for cultivating car- 
rots and other root-crops in drills, cleaning eight or ten 
rows at once. It is furnished with sharp, horizontal 
blades, which run beneath the surface, and shave off and 
destroy all the weeds within an inch of the rows of young 
plants. These rows, having been planted by means of a 
drilling-machine, are straight, and perfectly parallel, and 
the operator has only to watch one row, and guide the 
blades for that row, the apparatus being so contrived 
that the blades for the other rows shall run at the same 
distance from them. 

Fig. 158 represents an end view of this implement. It 
exhibits the apparatus by which the length of the axle is 

Fig. 158. 




Garrett's Horse-hoe— End view. 

altered to suit all kinds of planting ; by which each hoe 
is kept independent of the others, so as to suit the ine- 
qualities of the ground, and by which they can be set any 
width, from seven inches to thirty. It shows the oblique 
angle at which they run— this obliquity being easily al- 



148 MECHANICS. 

tered to any desired degree : this is effected by a move- 
ment of the upper handle, represented in the figure. By 
the lower handle, the whole is accurately guided. It is 
said that two men, one to lead the horse, and the other to 
guide the implement, will dress ten acres of root-crops in 
a single day, and that it has proved eminently a labor- 
saving machine. It can be used only on smooth land, 
free from stone. 

TWO-HORSE CULTIVATORS 

are made to run on two wheels, and the depth of the 
teeth is regulated by raising or lowering the frame-work 
that holds them. They have been much used for pulver- 
izing the surface of inverted sod, and fitting it for the re- 
ception of seed, but are likely to be superseded for this 
purpose by Shares' harrow. Modified so as to pass the 
two spaces between three rows of corn, they are known 
as double cultivators, and have now come into use for cul- 
tivating large fields, and are generally adopted for this 
purpose at the West. They accomplish twice the work 
of the single cultivator. They are of two kinds : those 
called the sulky cultivators, being furnished with a seat 
on which the driver rides, and the walking cultivators, 
without seat, the attendant walking behind. The former 
will accomplish more work in a day, with less fatigue to 
the driver ; the walking cultivators are better suited to 
rough, or sidling ground, and are cheaper. Many manu- 
facturers make them of different forms, both at the West 
and in some of the more eastern States. The best sulky 
cultivators cost about $75. 

comstock's rotary spader. 

This new machine, which has been used to some extent 
in the broad fields of the West, forks up the soil by means 
of a series of revolving teeth. It is drawn by two or 
four horses, according to its size and the strength of the 



comstock's rotary spader. 149 

animals, the driver riding on a seat. Sometimes two ma- 
chines are attached together, and both are driven by one 
man. It is used only on land free from sod, such as corn, 
or other stubble, and is not adapted to land containing 
stones or rocks. 

Its advantages are the following : Greater ease of 
draught, when compared with the plow, the chief source 
of friction being the thrusting of the teeth into the soil, 
while the friction of the plow at the mould-board is usu- 
ally equal to at least half the weight of the moving sod, 
added to half the entire weight of both plow and sod, on 
the sole in the bottom of the furrow, while more force is 
required to cut with the edge of the share than with the 
points of the rotary spader. Hence it is found to do 
twice or three times as much work with the same team as 
a plow. It does not form a hard crust in the bottom of 
the furrow, like the plow; and it leaves friable soils pul- 
verized ready for planting, without the use of the harrow. 

There are some serious drawbacks to the general intro- 
duction of this machine. Its cost exceeds ten times that 
of a good steel plow, while its complexity renders it more 
liable to strain or breakage, except in uniform and stone- 
less soils. It cannot be used in wet seasons, and pulver- 
izes such land only as is previously free from grass. It 
may, however, prove valuable on extensive farms. 

CLOD-CRUSHERS. 

In clayey soils, clods are often formed in abundance 
during the process of cultivation. These become very 
hard in dry weather, and prevent the proper extension of 
the fine roots of plants in search of nourishment, and also 
the intermixture of manure with the soil, without which 
it has been found that two-thirds, or even three-fourths, of 
the value of manure is lost to growing crops. 

Different modes of pulverizing the clods have been 



150 



MECHANICS. 



adopted. The simplest is the " drag-roller" represented 
in fig. 159. It is made of a log, or portion of a hollow 
tree, into which a common two-horse wagon tongue has 
been fitted, by which it is dragged over the ground with- 
out rolling, grinding to powder, in its progress, every clod 
over which it passes. The greater the diameter of the 

log, the less will 
be the liability of 
its clogging by 
gathering the 
clods before it. 
It may also be 
made of a half 
Fig. 160 represents 



Fig. 159. 




Clod-crusher. 



log, with the round side downward. 



Fig. 100. 




One-horse Clod-crusher. 



Fig. 101. 



a similar imple- 
ment for one 
horse ; this is used 
for working be- 
tween the rows 
of corn in cloddy 
ground. 

The use of these simple implements, by reducing rough 

fields to a condi- 
tion as mellow as 
ashes, has,in some 
instances, been 
the means of 
doubling the crop. 
It is necessary 
that the soil be 
dry when they 
are used, to pre- 
vent its packing 

CrosskHVs Clod-crusher. together. 

CrosskilVs Clod-crusher, first used in England, is a 
more powerful and more costly implement (fig. 161). It 




CLOD-CRUSIIERS. 



151 



consists of about two dozen circular cast-iron disks, 
placed loosely upon an axle, so as to revolve separately. 
Their outer circumference is formed into teeth, which 
crush and grind up the clods as they roll over the surface 
of the field. Every alternate disk has a larger hole for 
the axle, which causes it to rise and fall while turning 
over, and thus prevent the disks from clogging. Fig. 162 
represents this implement, as modified and manufactured 
in this country. It is used only where heavy clay soils 
prevail. 

This clod-crusher can be used only where the ground 
and the clods have become quite dry. Even then it packs 

Fig. 162. 




American Clod-crusher. 
the soil, and if followed by a harrow, with scarifier teeth, 
to loosen it again, it would prove an advantage. It is 
only in certain seasons that it is most successfully em- 
ployed, or when quite dry weather follows a wet spring. 
As thorough tile-draining is generally adopted, it becomes 
less necessary. 

The best clod-crushers are sold for about $125. 



THE ROLLER. 



This implement, now in general use, is employed for 
pressing in grass seed after sowing, for smoothing the sur- 
face of new meadows early in spring, and for other similar 



152 



MECHANICS. 



purposes. On light soils, it is most valuable, and may be 
used at nearly all times with safety. Heavy or clay soils 
will be crusted and injured if rolled while wet. The 



Fkr. 1G3. 




Field Roller. 
roller was formerly made of a single piece, or of a log of 
wood dressed to a true cylinder ; but this scraped the 
earth when turned to the right or left. A great improve- 
ment was made by cutting the single roller into two 
parts; and a still greater, by employing cast-iron, in sev- 
eral sections, as shown in fig. 163. The cost of cast 
rollers is about $85 to $100. 



CHAPTER XI. 

PLANTING AND SOWING-MACHINES. 

Sowing-machines, for wheat and other grains, possess 
great advantages over hand-sowing. All the seed being 
deposited by them at a nearly uniform depth, and com- 
pletely covered with earth, it vegetates and grows evenly, 
and the plants are uniformly strong and vigorous. A 
less quantity of seed is required, and the crop is heavier. 

WHEAT DRILLS. 

Several excellent grain drills are now manufactured and 
sold in this country, having much similarity in external 
appearance. One of the best and most widely known 



SOWING-MACHINES. 



153 



Fitf. 164. 




is made by Bichford <& Huffman, of Maccdon, N. Y. It 
is represented in 
the accompany- 
ing cut, showing 
eight dropping 
tubes. The mode 
by which the 
grain is dis- 
charged from the 
hopper down 

these tubes is ex- 
hibited in section in fig. 165 ; d being the interior of the 
hopper, bb a revolving wheel, the projecting rims of which 
form the bottom of the seed-holder ; 
the axle at a causes this wheel to 
revolve, and the small projections on 



the interior of the 

rim carry the seed 

to c, where it drops 

through an opening 

in the plate which 

forms the side of the 

seed-holder. The 

rapidity of discharge is perfectly con- 
trolled by wheel-work, which causes the 
axle a to revolve slowly or fast at pleasure. The 
seed-holder is divided into two parts by the wheel 
a b, as shown by cross section in figure 166 ; one 
part, d, containing wheat, barley, and other medium- 
sized grains, and the 
other, c, for corn, peas, 
and the larger seeds. 
This figure shows the 
opening in the side- 
plates, through which the grain is discharged. As these 
two divisions must be used on separate occasions, the 




Cross-section of Seed- 
holder. 




Cross-section of Bis ■ 
charger. 




Sliding Reversible Bottom of Hopper. 



154 MECHANICS. 

openings between them and the hopper are opened and 
closed at pleasure by a sliding bottom, with a single 
movement of the hand. This sliding bottom is shown in 
fig. 167, and forms hoppers with sloping sides, down 
which the grain passes freely. 

The ends of the tubes, which are shod with steel, are 
made to pass any desired depth into the mellowed soil, 
and depositing the seed, it is immediately covered by the 
falling earth, as the drill passes. This drill is furnished 
with an attachment for sowing plaster, guano, or any 
other concentrated manure, and also with a grass-seed 
sower. 

A great improvement has been made in the mode al- 
ready described, of discharging the seed ; formerly, seed- 
drills generally were furnished with a revolving cylinder, 
in the surface of which small cavities were made, for car- 
rying off and dropping measured portions of the grain ; 
these often broke or crushed the seed, and were liable to 
derangement. Others were furnished with circular, re- 
volving brushes, for pressing the seed through holes in 
the bottom of the hopper ; but this contrivance was im- 
perfect, and the brushes were liable to wear out. In the 
discharging apparatus of the drill just described, the 
seeds are never crushed, and the whole being substantially 
made of cast-iron, it may be run a lifetime. The best 
grain drills are sold for $80 or $90. 

seymoue's broadcast sower 

is an excellent machine for sowing plaster, ashes, guano, 
salt, or any other concentrated fertilizer, as well as com- 
mon grain and grass seed. The disagreeable, and even 
dangerous, as well as heavy and laborious work of sow- 
ing these manures by hand renders such a machine de- 
sirable on every farm. It is drawn by one horse, sows 



CORN PLANTERS. 



155 



ten feet wide, and the operator rides in a seat. Seymour's 
Plaster Sower sows these fertilizers, whether wet or dry. 
These machines are sold at about $70. 



Fig. 1G3. 



CORN PLANTERS. 

Among the best one-horse corn planters, which make 
one drill at a time, are Emery's, Harrington's, and Bil- 
lings'. The last-named, is represented in the annexed cut. 
It drops in hills, eleven inches apart in the row, or, if de- 
sired, twenty-two 
inches, the perfora- 
tions in the slides 
regulating the 

number of grains. 
It is so constructed 
as to drop any 
desired amount of 

Billings' Com Planter. plaster, guano, 01" 

other concentrated manure, without coming in contact with 
the seed. This, and other one-horse drills, are well adapted 
to planting fields of considerable size, for cultivating in 
rows but one way. On a larger scale, two-horse drills 
are employed. Wheat drills are often used for this pur- 
pose, employing only two of the tubes. Another class of 
corn planters, for planting in hills, the rows running both 
ways, consist of hollow tubes, which contain the seed, 
and which, by striking or pressing on the soil, drop and 
cover a hill at one stroke. 




TRUE S POTATO PLANTER. 



For field culture, this implement has proved an import- 
ant saver of hand labor. It is drawn by one horse, and 
cuts, drops, and covers the potatoes at one operation. It 
is usually employed, on ground which has been plowed 



156 MECHANICS. 

and harrowed only, the driver forming the drills by the 
eye, as the planting proceeds. Straighter rows may be 
made by first marking the land with a good corn-marker, 
and then employing a small boy to ride, directing him to 
keep the horse on the line. The driver has then only to 

Fig-. 1GX 




Time's Potato Planter. 



watch the working of the machine before him. If the 
ground is rough, or rather dry, it is better to furrow the 
land previously with a single horse, running the planter 
in these furrows. 

For using this machine successfully, the seed potatoes 
must be previously assorted, so that those of nearly equal 
size may be used at a time. It is common to assort them 
into two sizes, which may be done in winter, or on rainy 
days. Each potato passes the throat of the hopper sin- 
gly ; and if one in a bushel happens to be too large, it 
will choke the opening. After passing the hopper, each 
potato is sliced into pieces of the desired size, which 
then, one by one, drop down the hollow coulter, and are 
buried. The throat of the hopper is readily contracted 
or expanded, and adapted to any assorted size of seed. 
One man, with a horse, will plant several acres in a day, 
and if the ground be in good order, with nearly or quite 



HAND DRILLS AND SEED SOWEKS. 



157 



as much accuracy as by hand, and with more uniformity 
of depth. 




HAND DRILLS, OR SEED SOWERS. 

These are 2Teut savers of labor for sowing the seeds of 
ruta-bagas, carrots, 
field beets, and 
other farm root 
crops, besides peas 
and beans. One 
of the best in use 
is Harrington's, 
represented by fig. 
170, and made by 
F. F. Holbrook & 

Co., Boston. The Harrington's Hand Seed Soxver. 

side chains mark the rows, and it makes its own drill 
Ffc. 1-1. drops, and covers 

the seed with ac- 
curacy, at one 
operation. It is 
readily changed 
to the hand culti- 
vator, by remov- 
ing the dropper, 
and attaching the 
Harrington's Hand Cvltivator, cultivator teeth, 

shown in fig. 171. It then becomes a convenient imple- 
ment for running between the rows, in small fields. 




158 



MECHANICS. 



CHAPTER XIL 

MACHINES FOR HAYING AND HARVESTING. 



MOWING AND REAPING MACHINES. 

The cutting part of the mowers and reapers made at 
the present day consists of a serrated blade, as shown by 




Kniv 



fig. 172, which passes through narrow slits in each of the 
lingers, shown in fig. 173, forming, when thus united, 

Fi<r. 17.3. 



cutting 




the 
paratus, as 



Cutter-bar. 



Fisr. 174. 



ap- 
ex- 
hibited in the an- 
nexed figure, of 
Wood's Mowing- 
machine (figure 
174). When the 
machine is used, the motion of the wheels on wdiich it 
runs is multiplied by 
means of the cog- 
wheels, imparting 
quick vibrations, end- 
wise, to this blade, 
shearing oif the grass 
smoothly as it ad- 
vances through the 
meadow, like a large 
number of scissors 
in exceedingly rapid 
motion. Wood's Mower. 

The finger-bar, the most important part, now adopted 




M0WEES A2sD EEAPEES. 



159 



in all mowing and reaping machines, was invented by 
Henry Ogle, of Alnwick, England, in 1822, and his machine 
was put in successful operation, after much experimenting, 
by T. & J. Brown, of that place. But so strong was the prej- 
udice of the working people against labor-saving machine- 
ry, that they threatened to kill the manufacturers if they 
persevered ; and the enterprise for a time was given up.* 
The limits of this work permit only a brief notice of 
some of the chief 
points in mow- 
ers and reapers ; 
and a few ma- 
chines are refer- 
red to, out of a 
large number of 
kinds, which are % 
made in the dif- 
ferent States, ^ 
and which have 

proved them- The Kirby Machine as a Mower 

selves worthy of the confidence of farmers. 




n.tr. 170. 



The operation of 
mowing is shown in 
fig. 175, which rep- 
resents the Kirby 
mower, one of the 
best single -wheel 
machines, cutting a 
swath five feet 
wide, as fast as the 
horses advance. 
Buckeye Mower with Folded Bar. Various contriv- 

ances are adopted for lifting or folding the cutter-bar when 
the machine is not in operation, or in passing from one field 




* Woodcroft. 



160 



MECHANICS. 




to another. A neat and convenient form is used in the 
Buckeye Mower, represented in the accompanying cut, 
(fig. 176) where the bar is folded over in front of the 
driver's feet. 

In the mowing-machine, the cutting apparatus is nar- 
Fig. 177. row, causing the 

newly cut grass to 
fall evenly behind it, 
covering the whole 
surface of the 
ground. The reap- 
in fr-machine is simi- 
lar in construction, 
with the addition of 
a platform for hold- 
Kirby Reaper, with Hand Bake. j n<T || ie <rrain as if. 

falls, as shown in the annexed figure of the Kirby machine, 
changed to a reaper (fig. 177). 

This figure represents the reel, which is attached to, 
and is worked by the machine, causing the grain, as it is 
cut, to drop smoothly Fig. 17S. 

upon the platform. 
"When a sufficient 
quantity has collected 
there, it is swept off 
by the hand rake, and 
is afterwards bound in 
a sheaf. The annexed 
cut exhibits the Cayu- 
ga Chief, (an excellent Cayuga Chief— Combined Mower and Reaper. 
two-wheeled machine) as a reaper, in which the opera- 
tion of hand-raking is distinctly represented. 

SELF-F.AKING KEAPEES. 

Mowing-machines need but one man for their man- 
agement, who merely drives the horses that draw it. 




SELF-RAKING HEATERS. 



161 



Reapers, as usually made, require another man besides the 
driver, to rake off the bunches of cut grain, which is se- 
vere labor. Various self-raking contrivances have been 
used to obviate this labor, several of which have been 
made to do excellent work, and arc coming into general 
use. 

One of the first successful self-raking attachments to 
the reaper was that used by Seymour & Morgan, of 
Brockport, K Y. It was one of the kind which sweeps 
across the platform, in the arc of a circle, delivering the 
gavel at the side of the machine. The ordinary reel is 
used with this class of rakes. An objection to them is, 
that the grain is seized for throwing off at a point behind 
the cutters. Owen Dorsey introduced an improvement in 
the form of what are termed reel-rakes, which strike the 
grain forward of the cutters. A series of sweeps or 
beaters were employed, combined with one or more rakes, 
the gavel being delivered from the platform at each cir- 
cuit of the rake. At first, the horizontal motion of these 

arms prevented the 
driver from riding 
on the machine. An 
improvement was ef- 
fected, so that the 
arms and rakes, after 
passing the platform, 
were made to rise to 
a nearly vertical posi- 
tion, thus passing the 
driver freely. The 



Fie:. 179. 




The Kirby Self-raJcer. 



accompanying engraving, (fig. 179) representing the self- 
raker used on the Kirby machine, shows the position of 
the arms when in motion — one of them serving as a rake 
at each revolution. There are several modifications of 
this class of rakes, made by different inventors. Marsh's 
machine consists of beaters and rakes combined, and de- 



162 



MECHANICS. 



livers one or more gavels at each revolution, according to 
the number of rakes used at a time. Johnson's rake is 
furnished with rake-heads for each of the arms, which are 
so arranged as to dip low into the grain forward of the 
cutters, and afterwards to rise in passing over the plat- 
form. To discharge the grain, the driver uses a latch- 
cord and lever, so that the path in which the rake travels 
is changed by opening a switch or gate, permitting one of 
the rakes to pass low enough to sweep the platform. The 
Cayuga Chief, Buckeye, Hubbard, and other reapers, use 
this self-raker. The JLirby machine employs a self-raking 
attachment of its own, already represented in fig. 179. 
Two or three of the arms, or beaters, at the option of the 
driver, bring the grain on the platform ; the other one or 
two carry the rake-head. The driver may throw off a 
gavel, or two gavels, at each revolution; or the rake may 
"be made to run continuously, at regular intervals, without 
attention on the part of the driver. The arms, or rakes, 
are so made as to be adjustable to the height of the grain. 
The Dropper is a simple contrivance, (represented in 
the annexed en- Fig. iso. 

graving) consist- 
ing of a light plat- 
form, which holds 
the grain until the 
gavel is large 
enough, when it 
suddenly drops 
and discharges it. 
It is much used at 

the West and al- Cayuga Chief with Dropper. 

though hardly so perfect as some self-rakers, is preferred 
by many farmers, the gavels being delivered behind the 
machine, and thus keeping the binders up to their work, 
in clearing the way for the next passage of the reaper. 




ttlt/VMT- 



marsh's harvester. 



163 



BINDERS. 

Several machines for binding grain have been invented, 
possessing considerable merit, but so far they do not ap- 
pear to be adapted to general introduction. 

Marsh's Harvester, much used at the West, is so con- 
structed, that two men may readily bind as fast as the 
harvester does its work. The binders stand on a small 

platform, furnished 
with a guard or rail, 
and the grain, as fast 
as it is cut, is carried 
up by an endless 
apron to a platform, 
where each man alter- 
nately makes his 
band, and receives 
and binds his sheaf. 
As they expend no 
time in stooping, or 
in passing from gavel to gavel, they are enabled to work 
with ease and rapidity. The weight is only that of one 
man more than on a hand-raker. 

Headers are reaping-machines employed for cutting the 
heads of wheat with a small portion of the straw, leaving 
most of the straw standing. They are usually driven by 
four horses, and are thrust forward ahead of the team. A 
two-horse wagon, in addition, is driven along side, to re- 
ceive from an endless apron the heads, as they are cut by 
the reaper. They are only used on the extensive fields of 
the West, and a difference of opinion prevails as to their 
general value. 

DURABILITY AND SELECTION. 

Mowing and reaping-machines, being complex, or made 
up of many parts, would soon be broken and destroyed, 




104 MECHANICS. 

if the resistance they meet with were irregular and full of 
obstructions, like those which the plow encounters. 
Standing grain and grass present a soft and uniform re- 
sistance, and hence, well-made machines will last several 
years without much repair. The Report of the Auburn 
trial of mowers and reapers gives five years as the aver- 
age " lifetime " of these machines. Much will depend on 
the amount of work performed in a season ; an extensive 
farmer states, that he usually cuts about five hundred 
acres with each machine before it needs renewing. Much, 
also, depends on the care which the machines receive ; 
such as keeping them always well sheltered from the 
weather, and thoroughly cleaning every part, and care- 
fully wiping the journals and bearings before they are laid 
aside for the season. 

In selecting mowers and reapers, there are several 
points which the purchaser should carefully observe ; as, 
for example — 1. Simplicity of construction. 2. Use of 
best material for knives and other parts used in manufac- 
ture. 3. Finish and perfection of gearing and running 
parts. 4. Durability, as proved by use. 5. Ease of 
draught. 6. Freedom from side draught. 7. Quality 
of work. 8. Ease of management. 9. Convenience 
and safety of driver. 10. Adaptation to uneven sur- 
faces. A part of these points can be fully determined 
only by thorough trial ; and it is always safest to 
purchase of those manufacturers whose machines have 
been long enough in general use to establish their char- 
acter in these respects. Fortunately, there are many in 
different parts of the country, who have secured a good 
reputation, from whom machines, or parts for repairs, may 
be obtained without sending long distances. The report 
of the Auburn trial, in 1866, states, that out of twenty 
different mowing-machines, which were tried on a rough 
meadow, every one, with two exceptions, " did good 
work, which would be acceptable to any farmer ; and the 



HAY TEDDERS. 



1G5 



appearance of the whole meadow, after it had been raked 
over, was vastly better than the average hand mowing of 
the best farmers in the State." Since that trial, a con- 
tinued improvement in manufacture has been taking place, 
and the machines are becoming more perfect. 

The price of a good two-horse mowing-machine is 
about $120 ; and of a combined mower and reaper, about 
$170. 

HAY TEDDIXG MACHEN~ES. 

Machines for stirring up and turning the drying hay 
have long since been known and used in England, and a 
few were introduced into use in this country. But as 
they were heavy and cumbersome, they never came into 
common use. A 
few years since, 
Bullard'sHayTed- v 
der was invented, 
and has been wide- 
ly used. It scatters 
and turns the hay 
with great rapidi- 
ty, and consists of 
several forks, held 
nearly upright, but 
worked by a com- 
pound crank, so as 

to scatter the hay 

. ~ , . Billiard? s Hay Tedder. 

in the rear ot the 

machine. The close resemblance of the movement of 

these forks to the energetic scratching of a lien presents 

a ludicrous appearance to one who sees it for the first 

time. The use of the tedder is found greatly to hasten 

the drying process, especially on heavy meadows, and to 

enable the farmer to secure his hay in so short a time as 

frequently to avoid damaging storms. 




166 



MECHANICS. 



A new machine, remarkable for its simplicity and per- 
fection of working, is the American Hay Tedder, made 
by the Ames Plow Company, of Boston. It is repre- 
Fjcr ls3 sented in the 

accompanying 
cut. It is furnish- 
ed with sixteen 
forks, attached 
to a light reel in 
such a manner 
that they re- 
volve rapidly, 
with a rotary, 
continuous, and uniform motion. It never clogs, may be 
easily backed, and readily passes over ordinary obstruc- 
tions, without any attention on the part of the driver. 

Hay tedders should be used on the meadow about 
three times a day, which will enable the farmer to cut his 
crop in the morning, and draw it in the same day ; giving 
him, also, more uniformly dried, and better hay. 
The price of hay tedders varies from $75 to £100. 




Tlie American Hay Tedder. 



HOESE HAY-RAKES. 



The simplest and original form of the horse-rake is 
represented in fig. 184. It was made of a piece of strong 
scantling, three inches square, tapering slightly toward 
the ends, for the purpose of combining strength with 
lightness, and in which were set horizontally about fif- 
teen teeth, twenty-two inches long, and an inch by an 
inch and three-fourths at the place of insertion, tapering 
on the under side, with a slight upward turn at the 
points, to prevent running into the ground. The two 
outer teeth were cut off to about one-third their first 
length, and draught-ropes attached. If these pieces were 



HORSE HAY-HAKES. 



167 



too short, the teeth were hard to guide ; if too long, the 
rake was unloaded with difficulty. Handles served to guide 



Fig. 184. 




Simple Horse-rake. 

the teeth, to lift the rake from the ground in avoiding ob- 
structions, and to empty the accumulated hay. 

In using this rake, the teeth were run flat upon the 
ground, passing under, and collecting the hay. When 
full, the horse was stopped, the handles thrown forward, 
the rake emptied and lifted over the windrow thus formed. 
The windrows, as in other horse-rakes, were made at 
right angles to the path of the rake, each load being de- 
posited opposite the last heap formed, in previously cross- 
ing the meadow. A few hours' practice enabled any one 
to use this rake without difficulty; the only skill required 
was to keep the teeth under the hay, and above the 
ground. 

In addition to raking, this implement was employed for 
sweeping the hay from the windrow, and drawing it to the 
Istack. It was also useful for cleaning up the scattered 
hay from the meadow, at the close of the work ; for rak- 
ing grain-stubble, and for pulling and gathering peas. If 
made of the toughest wood, and with the proper taper in 
the main parts for lightness and strength, according to 
the principles already pointed out in a previous chapter, 
it was easily lifted, and its use not attended with severe 
labor. 



1G8 



MECHANICS. 



This simple horse-rake has nearly gone out of use, and 
yet, on account of its simplicity and cheapness, it is wor- 
thy of being retained on small farms, and especially on 
meadows with uneven surfaces. The cost need not be 
more than three or four dollars. From twelve to fifteen 
acres could be raked with it in a day. 

The Revolving Horse-rake (fig. 185) was next generally 
adopted, possessing the great advantage of unloading 

Fi". 1S5. 




Revolviyig Horse-rake. 

without lifting the rake or stopping the horse. It has a 
double row of teeth, pointing each way, which are brought 
alternately into use as the rake makes a semi-revolution 
at each forming windrow, in its onward progress. They 
are kept flat upon the ground by the pressure of the 
square frame on their points, beneath the handles ; but as 
soon as a load of hay has collected, the handles are 
slightly raised, throwing this frame backwards, oif the 
points, and raising them enough for the forward row to 
catch the earth. The continued motion of the horse 
causes the teeth to rise and revolve, throwing the back- 
ward teeth foremost, over the windrow. In this way, each 
set of teeth is alternately brought into operation. The 
cost of this rake is from $7 to $10, and twenty acres 
or more could be raked with it in a day. 

A further improvement has been made in the revolving 
rake, by attaching it to a sulky, on which the operator 



REVOLVING HORSE-RAKES. 



169 



Fig. ISO. 




Fig. 187. 



rides, enabling him to do a larger amount of work with 
less fatigue. There are several modifications, some of 

which place the rake 
in front of the sulky 
wheels, and others, 
in the rear. One of 
the best and most 
widely used is 
" Warner's Sulky 
Revolver," manu- 
factured by Bly- 
myer, Day & Co., of Mansfield, Ohio, and by others. It is 
represented in the annexed cuts, fig. 186 showing it in 
the operation of raking, and fig. 187, the same machine, 
with the rake thrown 
upon the wheels, for 
driving: from field to 
field. The head is 
the same as the com- 
mon revolving rake- 
head — the teeth be- 
ing tipped with mal- 
leable iron. The 
rake is operated by _ 
means of a lever, at- 
tached to a journal at the centre of the rake-head. By 
means of cams, stop, and spring, the lever and head are 
entirely at the will of the operator. A slight pressure, 
equal to seven or eight pounds, on a lever, causes the 
rake to revolve ; and it is also readily elevated for back- 
ing, or for passing obstructions. 

An important advantage of this rake is, its gathering 
the hay free from gravel and earth ; also its cheapness 
recommends it — the price being about $35. 




8 



170 



MECHANICS. 



SPRING-TOOTH EAKE. 



The original form of the spring-tooth rake is shown in 
fig. 188. The teeth were made of stiff, elastic wire, on 

the points of which 
the rake ran, and 
not on the flat 
sides, as in those 
already described. 
They bent in pass- 
ing an obstruction, 
and sprung back 
again to their place. 
This rake was un- 
loaded by simply 
lifting the handles, 
which was easily 
done, the rake be- 

Vprmj-tnth Horsc-rake. mg J^J^ and 

about one-half the weight being sustained by the horse. 

All the spring-tooth rakes made and used at the present 
time are attached to wheels, and a seat is furnished for 
the driver. There are many patented modifications, some 
possessing advantages of greater simplicity, or ease of 
management ; but all appear to be good and efficient 
rakes, enabling the operator to gather about twenty-five 
acres in a day. 

Among the best of the spring-tooth rakes is that of 
Hollingsworth, made by Wanzer & Cromwell, of Chicago, 
and represented in the accompanying engraving. Each 
tooth is separate, and may be readily replaced. As soon 
as the rake is loaded with hay, the driver, by touching 
the lever before him, drops it at the line of the windrow. 
The cost is about $45, 




THE HAT-SWEEP. 

Fisr. 180. 



171 




nollimjmoniC s Spring-tooth Bake. 
THE HAY-SWEEP. 

Where the hay is secured in stacks, or in hay-barns 
situated contiguous to the meadow, the use of the hay- 
sweep, in connection with the horse-fork, would probably 

enable two or three 

men, and two feoys, 

with three horses, to 

draw and pack away 

thirty tons a day, or 

more. The hay-sweep, 

invented many years 

Hay-Sweep. ago by W. R. Smith, 

of Macedon, N". Y., is but little known. The accompanying 

figures (190 and 191) exhibit its construction and use. It 

is essentially a large, stout, coarse rake, with teeth pro- 




172 



MECHANICS. 



jecting both ways, like those of a common revolver ; a 
horse is attached to each end, and a boy rides each horse. 
A horse passes along each side of the windrow, and the two 

Fisr. 191. 




Hay-siveep in Operation. 
thus draw this rake after them, scooping up the hay as 
they go. When 500 pounds or more are collected, they 
draw it at once to the stack, or barn, and the horses turn- 
ing about at each end, causing the gates to make half a 
circle, draw the teeth backward from the heap of hay, 
and go empty for another load — the teeth on opposite 
sides being thus used alternately. To pitch easily, the 
back of each load must be left so as to be pitched first. 

The dimensions should be about as follows : — Main 
scantling, below, 4 by 5 inches, 10 feet long ; the one 
above it, same length, 3 by 4 inches ; these are three feet 
apart, connected by seven upright bars, 1 by 2 inches, and 3 
feet long. The teeth are flat, lh by 4 inches, 5 feet long, 
or projecting 2^ feet each way ; they are made tapering 
to the ends, so as to run easily under the windrow. A 
gate, swinging half way round on very stout hinges, is 
hung to each end of this rake, and to these gates the 
horses are attached. Each gate consists of two pieces of 
scantling, 3 inches square, and 3 feet long, united by two 
bars of wood, 1 by 2 inches, and a third, at the bottom, 3 
inches square, and tapering upwarols, like a sled runner; 



HORSE HAY-FORKS. 



173 



these runners project a few inches beyond the gate. The 
whiffle-trees are fastened a little above the middle of the 
gate, and should be raised or lowered so as to be exactly- 
adjusted. This machine may be made for $6 or $7. 

In using, not a moment is lost in loading or unloading. 
No person is needed in attendance, except the two small 
boys that ride the. horses. If the horses walk three miles 
an hour, and travel a quarter of a mile for each load, they 
will draw 12 loads, or three tons an hour, or thirty tons 
in ten hours, leaving the men wholly occupied in raising 
the hay from the ground, by means of another horse, with 
the pitchfork. 

It will be obvious, that this rapid mode of securing hay 
will enable the farmer to elude showers and storms, which 
might otherwise prove a great damage. 

HORSE HAT -FORKS. 

Every farmer who has over pitched off from a wagon 
in one day ten or twelve tons of hay 
is aware that no labor on the farm 
can be more fatiguing. The horse- 
fork, in its various forms, which, to a 
considerable extent, has been brought 
into use, has afforded great relief, 
severe labor being not only avoided, 
but much greater expedition attained. 
The effective force of a horse is, at 
least, five times as great as that of a 
stout man; and if half an hour is 
usually required for him to unload a 
ton of hay, then only six minutes 
would be necessary to accomplish the 
same result with horse-power. Actual 
experiment very nearly accords with 
this estimate. 



Fin. 192. 




Original, Horse-fork. 



A simple form of the horse pitchfork was described in 



174 



MECHANICS. 



the Albany Cultivator, in 1848, from which a subscriber 
in Bradford County, Pa., made the first used in that re- 
gion. Some years later, he stated that there were at least 
two hundred in use. The preceding figure represents 
this simple and original fork. A is the head, twenty- 
eight inches long, and two and a half inches square, made 
of strong wood. A G is the handle, five and a half feet 

long, mortised 
into the head, 
with an iron 
clasp or band of 
hoop iron fitting 
over the head, 
and extending 
six inches up the 
handle, secured 
bv rivets. The 
prongs of the 
fork are made of 
good steel, one- 
half an inch 
wide at the 
head, twenty 
inches long, and 
eight inches 
apart, with nuts to screw them up tight. Rivets are placed 
on each side of the middle ones, to prevent the head from 
splitting. The rope is attached to staples at the ends of 
the head. The single rope D extends over a tackle-block, at- 
tached to a rafter at the peak of the barn, about two feet 
within the edge of the bay. The rope then passes down 
to the bottom of the door-post, under another tackle- 
block, and to the outside of the barn, where the working 
horse is attached to it. A small rope or cord G is attached 
to the end of the handle, by which it is kept level, as it 
ascends over the mow. The cord is then slackened, and 




Pitching Hay through a Window with Horse-power. 



gladding's hoese-foek. 



175 



the hay tilts the fork, discharging its load. The horse is 
then backed up, ready for another fork load, the only labor 
of the workman being to drive the fork into the hay and 
keep the cord steady. An important advantage is gained, 
besides the saving of time ; for the man on the load, being 
relieved from the severe labor of pitching, is fresh and 
vigorous for throwing on another load in the field. 

The length of the handle made it difficult to use this fork 
under low roofs, and an improvement was made by Glad- 
ding, by which the head of the rake only was tilted, 
leaving the handle in its horizontal position. A hinge- 
joint is placed at the connection of the head and handle, 



so that, at any 




Gladding's Hay-fork, 



moment, by a jerk 
on the cord which 
passes up a bore 
in the handle, the 
fork is dropped, as 
shown in fig. 194, 
and its load depos- 
ited. This may be 
done instantane- 
ously, at the mo- 
ment it happens to 

be sw T ung to the most favorable spot. Its weight causes the 
head to fly back of its own accord, and resume its former 
position, ready for another forkful. The rope suspending 
the fork should be fastened to the highest portion of one 
of the rafters, over the mow, and a smooth board should 
be placed, vertically, against the face of the mow, for the 
hay to slide on as it ascends. By attaching this rope in 
front of, and within a window, the hay is carried with 
ease into the window, and thus lofts over sheds, carriage- 
houses, etc., where the old horse-fork could not be used, 
are filled by the use of Gladding 's improvement. This is 
one of the best forks, adapted to all kinds of pitching, 



176 



MECHANICS. 



and has unloaded a ton of hay in about three minutes; 
and over a beam twenty-two feet high, under a low rafter, 
in about nine minutes. 

In using horse forks, as already stated, their operation 
is much facilitated by providing a board slide, to be 
placed vertically against the face of the mow, or bay, on 
which the hay moves upward. In pitching into a win- 
dow, the bottom of this board slide should be placed out 
a few feet from the building, and the top should rest on 
the base of the window. When convenient, the back 
end of the wagon load should be placed towards the win- 
dow. There is no limit to the height at which the pitch- 
ing may be easily performed — giving the use of the 
horse-fork a great advantage over hand pitching ; and 
barns, with high posts, may be built for the storage of 
hay. 

Other forms have been adopted for pitching under roofs, 
by using shorter handles. One of the best is Palmer's 

Fig. 195. Fi"r. 193. 




Palmer's Fork, 

Fork, made by Wheeler & Co., Albany, and Palmer & Co., 



DOUBLE FORKS. 



177 




Chicago, which is represented in the accompanying figures, 
Fig. 197. Fig. 193. the right-hand one 

showing its posi- 
tion when ascend- 
ing, loaded with 
hay ; the left-hand, 
with the knee-joint 
brace contracted, 
by jerking the cord 
for emptying the 
load. Still another, 
known as Myers* 
Elevator, is shown 
in fig. 197, in its 

Myers 1 Hay Elevator. position when lift- 

ing the hay, and fig. 198, when dropping it. The head is 
iron, and it is a strong and simple fork. 

DOUBLE FORKS. 

The double forks clasp the load of hay like the claws of 
a bird. This class Fi s- 1CJ,J - 

of forks may be 
used for pitching 
over a beam, with- 
out a board facing. 
They are better 
adapted to pitch- 
ing short straw, 
especially those 
which like Ray- 
mond's,have sever- 
al teeth ; but more 
time is required for 
thrusting in the 
two forks than one. 
One of the simplest is Beardslei/s Hay Elevator, (fig. 199) 
8* 




178 



MECHANICS. 



which sufficiently explains itself. 



Fi£. 200. 




Raymond's Fork. 

moneys Elevator, made by J. II. 
Y., consists of two three-pronged 
forks, connected together by a 
hinge, (fig. 200) and is one of the 
best double forks. Connected 
with this fork is a ready con- 
trivance for attaching it, in a 
moment, to any rafter or beam. 
The accompanying figure (fig. 
201) represents the clamp by 
which this attachment is effected, 
and fig. 200 shows the elevator, 
secured in position from two 
points, with the forks opened, 
when dropping their load. It is 
raised and lowered by the double 
ropes passing over the two fixed 
pulleys, and the one on the 
elevator — the horse moving twice 
as fast as the load is raised. 
Thus attached to two beams, the 



The "Little Giant" 
Fork resembles the 
claws of a bird, and 
has a fluted, tubu- 
lar, cast head, the 
single grasping- 
tooth being double- 
jointed, and per- 
mitting it to enter 
the grain freely. 
On the movement 
of the horse, it is 
brought to its 
place, grasping its 
load firmly. ^ay- 
Chapman, Clayville, N. 

Fiff. 201. 




Grappling Irons and Hoisting 
TasMe. 

load may be run hori- 



HARPOON FORKS. 



179 



zontally, as well as raised vertically, as more fully ex- 
plained under the head of Stacking. By the single fasten- 
ing? ( fi g- 201) the fork is only raised vertically. 



HARPOON FORKS. 



For pitching hay exclusively, or any material which 
hangs well together, the harpoon forks do their work 
more rapidly than any other, but they are not adapted to 



Fig. 205. 



Fig. 204. 



Fig. 202. 



Fig. 203. 





Walker's Harpoon Fork. Sprout's Fork. 

short straw. Walker's harpoon, made by Wheeler,Melick 
& Co., Albany, is a straight bar of metal, appearing al- 
most as simple as a crow-bar, (fig. 202. Its point is driven 
into the hay as far as desired, when a movement at the han- 
dle is made, which turns up the point at right angles, (fig. 
203,) enabling it to lift a large quantity of hay. A modifica- 
tion has spurs, which are thrown out on opposite sides. 
The combined fork and knife invented by Kniffen & Har- 



180 MECHANICS. 

rington, of Worcester, Mass., is an excellent hay-knife, 
when folded, as in fig. 205, and an efficient elevator, when 
opened, as in fig. 204. It is well adapted to the use of 
farmers who have nothing but hay to pitch, and plenty of 
room for the elevator to swing in. At the Auburn trial, 
this fork discharged a load of hay weighing twenty-three 
hundred pounds, over a beam, in two minutes. 

The prices of horse-forks, of different kinds, vary from 
$10 to $20. 

HAY CARRIERS. 

An inconvenience results from the fixed position of a 
hay-fork, preventing the hay from being distributed over 
different parts of a broad bay, except so far as it may be 
swung to the right or left, and the load dropped at a sig- 
nal. Several hands are sometimes required to spread this 
hay evenly, as it is rapidly discharged by the horse-fork. 
Another disadvantage is, the required narrowness of the 
bay, which cannot well be more than twenty or twenty- 
five feet wide. These objections are obviated, and the 
hay carried fifty or a hundred feet horizontally, by means 
of Hick's Elevator and Carrier, of which the following 
clear and full description is given in the Report of the 
Auburn Trial of Implements : — " It consists of a track, 
made of 2 by 5-inch plank, fastened to the rafters a few 
inches below the ridge of the barn by 1^-inch square 
strips and twelve-penny nails. Upon this track runs a 
car ; a rope passes through it, and through a catch pulley 
attached to a horse hay-fork, then back to the car ; the 
other end passes back to the end of the barn, and returns 
through pulley wheels to the barn floor, to which end a 
horse is attached. 

By a peculiar arrangement of the car, it is held in posi- 
tion on the track, over the load to be unloaded, until a 
forkful of hay is elevated to it, when it is liberated from 



HAY CARRIERS. 181 

its position, and the fork made fast to the car in one oper- 
ation, then it moves off on the track very easily, and any 
distance you may choose to have it carried ; the operator, 
by pulling a cord, trips the fork, and the horse, turning 
around, walks or trots back to the place of starting ; the 
car is pulled back to its position by the trip cord, when 
the fork descends for another load. 

The fork comes back so easily and quickly that the 
horse can be kept in motion continually, elevating from 
300 to 400 pounds of hay, and carrying it forty to fifty 
feet in a horizontal direction, and returning for another 
load in less than a minute. 

Its advantages over the old mode are : 

1st. — The hay can be carried into the second, third, and 
fourth bays from the wagon, as easily as into the first, 
thus saving a large amount of labor in the mows. 

2d. — The hay is elevated perpendicularly from the load, 
thus obviating the friction caused by dragging the forkful 
of hay over and against the beam ; also the danger of 
tripping or breaking the fork as it is drawn over the beam. 

3d. — The car and fork return so easily, the fork drop- 
ping in the middle of the load, ready to be thrust into the 
hay immediately ; whereas, in the old method, it is very 
hard work to get the fork back, if the hay has been car- 
ried any distance. 

4th. — The horse turns around, and walks or trots back 
to the place of starting, instead of backing, thus saving 
much labor to both horse and driver. 

5th. — The hay need be elevated only high enough to 
clear the highest beam, when it can be carried horizon- 
tally, until the mows are more than half full, when, by 
shortening a rope, the fork can be made to pass along 
only sixteen inches below the very peak of the barn. 

6th. — It requires but very little force to carry the hay 
horizontally, whereas, by the old methods, it requires 
more force to carry it horizontally than to elevate it. 



182 



MECHANICS. 



Fig. 206. 



7th. — By extending the track four feet beyond t'he end 
of the building, hay can be elevated and carried into 
long, low hovels, or cow barns, when no other arrange- 
ment would work at all. 

The car is small, and the track light and simple ; a 
weight has been lifted of 1,0S0 pounds by it at one time, 
with a pair of mules." 

By using a strong car, it may be employed for unload- 
ing coal from a boat. 

Building Stacks. — Three long poles may be used for 
this purpose, securely chained at the top, and spread in 
the form of a tripod. The one to which the lower pulley 
is attached should be set firmly into the ground, to pre- 
vent displacement by the outward draught. Holes are 
bored into the poles at convenient distances, and cross 

pieces secured to them, for holding 
the board slide, and permitting it 
to be gradually raised, as the stack 
goes up. The hay may be pitched 
from the ground as well as from a 
load, without inconvenience, to any 
height. 

Instead of chaining the poles to- 
gether, they may be firmly secured 
by using two stout clevises, the 

bolts of which are passed through 
Mode of Cmpling the Poles. mgQt hol ^ near the upper endg 

of the poles, (fig. 206). 

Palmer's Hay Stacker, represented in fig. 207, has 
been much used at the West, where large quantities of 
hay are deposited out of doors. It first elevates the hay, 
and then swings it around over the stack, dropping it 
where desired. It docs not drag the hay against the 
side of the stack, requires no staking down to prevent 
tipping, and is easily drawn on the sills as runners, to any 
part of the farm. The horizontal motion of the crane is 




palmer's hay stacker. 



183 



Fte. so- 



effected as follows : — Two ropes are attached to the whiffle- 
tree, one, a strong one, to elevate the hay, running on the 
pulleys at B, C, and D ; and the other, a smaller one, pass- 
ing the swivel pulley at A, on the 
end of the lever _Z?, extending from 
the foot of the upright shaft. This 
cord then passes up and over a 
pulley above the weight K The 
weight is about four pounds, and is 
attached to the end of the smaller 
cord. At the same time that the 
horse, in drawing, elevates the fork 
with its load of hay, the weight 
E is raised until it strikes the pul- 
ley, when the power 
of the horse becomes 
applied to the end of 
the lever JB, causing 
it to revolve, and 

swing the hay over '^^ = "^^^^ e * =tx ^ J *^ 

the Stack. As the Palmer's Hay Stacker. 

horse backs, the weight drops again to the ground, 
taking up the slack rope from under the horse's feet, and 
the weight of the fork causes the arm of the derrick to 
revolve back over the load. The intended height for 
raising the hay, before swinging, is regulated by length- 
ening or shortening the smaller cord, as the arm will not 
revolve until the weight strikes the pulley under the 
head block. T. G. & M. W. Palmer, of Chicago, own 
this invention, and furnish the smaller parts of the ma- 
chine, the heavier being easily made on the farms where 
intended to be used. 

Fig. 208 shows the manner in which Raymond's Ele- 
vator is mounted for stack building. These poles need 
not be so heavy as when three poles alone are used. They 
are kept from being drawn over towards each other in 




184 



MECHANICS. 



elevating heavy loads, by lashing the lower end of each 
outer pole to a strong stake, driven into the ground 
obliquely, by first making a hole with a crow-bar. It is 
convenient to place the two pole tripods sufficiently dis- 
tant from each other to give room for the stack, or rick, 

Fiff. 208. 




Fork on Poles for Building Stacks. 



and to allow the wagon to pass within them. The eleva- 
tor first lifts its load, and then carries it along the rope, 
till the man on the load drops it by a jerk of the cord. 
This apparatus is made by J. II. Chapman, of Clayville, 
N. Y. 



HAY PRESSES. 



Among the best Hay Presses in the country is the one 
manufactured by L. & P. K. Dederick, Albany, and rep- 
resented in the annexed engraving. It is worked by one 
or two horses, operating with great force by means of 
the arms on each side, which are connected with toggle- 
joint levers, explained in a former part of this work. The 
hay is thrown in from the upper platform, and when re- 
duced to compact bales, by means of the powerful force 
which this press gives, is taken out at the lower. In order 
to prevent the necessity of the horses running back at 



pedeuick's hay pkess. 

Fijr. 209. 



185 




DedericVs Hay Press. 
the pressure of every bale, Dederick's patent capstan (fig. 
210) is employed with this press. 
The horse or horses, in passing 
around, wind up the rope on a 
horizontal wheel or drum. The 
possibility of any accident by 
slipping backwards is prevented ^ 
by the pawl or anchor, E, at the rjjpg|gjg 
end of the lever, When the 




186 MECHANICS. 

pressure is completed, the driver touches the upright rod, 
and detaches the wheel or drum, by which the rope is 
drawn backwards, without stopping the horses, which 
continue to walk around the circle. 

This capstan answers an admirable purpose in using 
the common horse hay-fork, by obviating the necessity of 
backing up at every forkful. 

The New York Beater Press Company, of Little Falls, 
manufacture a press, working like a pile engine, and re- 
ducing the hay to a degree of compactness nearly equal 
to that of solid wood. These bales are well adapted to 
long conveyance by land or shipment to foreign ports. 

Hay Loaders. — Several of these, of different construc- 
tion, have been tried to a limited extent, but, so far, the 
experiments have been but partially successful, or the 
machines have not proved themselves fully adapted to 
general use. Their expense, when compared with the horse- 
fork, and, to some degree, their cumbersome character, 
have proved objections. They mostly require very smooth 
meadows, are often difficult to work in the wind, and 
those constructed on the endless-rake principle are found 
to carry up small stones or gravel into barley, endangering 
the thrashing machine. Further ingenuity and labor on 
the part of inventors appear to be required, to place them 
generally within the reach of farmers. 



CHAPTER XIII. 

THRASHING, GRINDING, AND PREPARING PRODUCTS. 
THRASHING MACHINES. 

The old mode of beating out grain with the hand flail, 
(fig. 211,) has now nearly passed away, and thrashing 
machines have come into general use. 




VALUE OF THRASHING MACHINES. 187 

S. E. Todd makes the following statement relative to 
the saving of labor effected by these machines: "I have 
thrashed a great deal of grain of all kinds, with my own 

flail; and I have talked with 
others who have been accustomed 
to thrash their grain with flails, 
and I have come to the conclusion 
thr.t the following figures rep- 
resent a fair average as to the 
quantity of grain that an ordinary 
laborer will be able to thrash and 
clean in a day, viz. : Seven bushels 
An Old Flail. of wheat, eighteen bushels of oats, 

fifteen bushels of barley, eight bushels of rye, and twenty 
bushels of buckwheat. In order to make this more intelligi- 
ble, it will be necessary to double the number of bushels 
that one man is able to thrash, as two men will be requir- 
ed to clean the grain with a fanning mill. 

"In order to labor economically and advantageously 
with a thrashing machine, two horses, at least, and three 
men are necessary. In most instances four or five men 
will be required, which will make a force equal to fifteen 
men with flails. Such a gang of hands, and two good 
horses, with such a thrasher and cleaner as Harder's, are 
capable of thrashing and cleaning of the same kind of 
grain to which allusion has been made, one hundred and 
seventy bushels of wheat, three hundred and twenty-five 
of oats, two hundred and twenty of barley, one hundred 
and eighty of rye, and two hundred and sixty of buck- 
wheat. Some manufacturers of thrashing machines fix 
the average day's work higher than these figures. In 
some instances, I will acknowledge that a span of horses 
and five men can do much more than the amount repre- 
sented by the foregoing figures ; yet I am satisfied that in 
the majority of instances they will not thrash and clean a 
greater number of bushels than I have indicated. But. 



188 



MECHANICS. 



even at the low figures that I have recorded, such a ma- 
chine as Harder's, or Palmer's Climax, or Wheeler, Melick 
& Co.'s, will be found to be a great labor-saving machine 
for thrashing all kinds of grain. 

"There is one consideration that should not be over- 
looked in this estimate, which is the much greater amount 
of labor performed, with far less fatigue. When one la- 
borer can perform the work of two or more workmen with 
less fatigue than has usually been required, a great point 
is gained." 

J. Stanton Gould, estimating from a large number of 
statements that a saving of five per cent of the grain is 
effected by using the machine, over thrashing by the flail, 
computes the aggregate annual saving in the United States 
to be over eight million bushels of wheat, two million 
of rye ; eight million of oats, and nearly a million of barley. 

For farms of moderate size, the endless-chain powers 
for driving thrashing machines are most convenient, being 

Fig. 212. 




E?idlcss-chain horse-power, driving a thrashing-machine, 

compact or requiring but little room, easily conveyed from 
one place to another, and readily applicable to sawing 
wood, cutting straw, and to various other purposes. Fig. 
212 represents a single horse-power, driving a small thrash- 
ing machine, with a simple, horizontal separator and straw 



TO MEASURE ENDLESS CHAIN POWER. 



189 



carrier; and fig. 213 shows a two-horse power, (Emery's,) 
with the wheel-work on which the endless platform runs. 
The power of these machines, and the amount of fric- 
tion in running them, may be easily ascertained by the 
rule, already given in a former part of this work, for de- 
termining the power of the inclined plane ; for the only 

Fig. 213. 




Two-horse Tread Power. 

difference between the endless chain and a common in- 
clined plane is, that in one the plane is fixed, and the body 
moves up its surface, and in the other the plane itself 
moves downward, and the weight or animal upon it re- 
mains stationary. The same principle applies in both cases. 

First, to ascertain the friction, let the platform be placed 
on a level, with the horse upon it; then gradually raise 
the end until the weight of the horse will just give it mo- 
tion. This will show the precise amount of the friction ; 
for if the end be elevated one-twentieth of its length, 
then the friction is one-twentieth the weight of the horse 
and platform. 

Secondly, to determine the power, when the end is still 
further raised, measure the difference between the height 
thus given and the length of the platform. If, for in- 
stance, the height of the inclination is one-eighth of its 
length, and the horse is found to weigh eight hundred 
pounds, then the power is one hundred pounds, or one- 
eighth the weight of the horse. 



190 



MECHANICS. 



Fig. 214. 



This rule will not, however, apply, when the draught 
of the horse is added to its weight ; for it usually happens 
that the weight alone is not sufficient, without placing the 
platform in too steep a position for the horse to work 
comfortably. He is, therefore, attached to a whiffle-tree, 
and to ascertain the power requires the use of the dyna- ^ 
mometer, in connection with the preceding mode. 

Great improvement has been made of late years in 

the appendages of 
thrashing machines. 
The large number 
of laborers formerly 
employed in raking 
and separating the 
straw, and placing it 
on the stack, is now 
dispensed with, and 
the whole done by 
machinerv, working: 
by the same power 
that drives the 
thrasher. Among the best and most widely known ma- 
chinery for this purpose is that invented by H. A. Pitts, 
and represented in a portable form by fig. 214. It sepa- 
rates the grain, cleans it, and carries the straw by means 
of the elevator, (shown folded in the cut,) to the top of 
the highest stack. 

The tread-power is successfully applied to churning, as 
shown in the cut, (fig. 215.) The employment of a sheep, 
of one of the larger breeds, has been found better and 
more convenient than a dog, as it is heavier, more quiet, 
less averse to the labor, and when the task is done, it is 
turned into the yard or pasture, where it is readily found 
next time. 

The cost of horse-powers and thrashers combined, of 
the different forms, varies from $225 to $400. 




fsrc^e^-*-*~<~- 



Pitts' Thrasher and Straw Carrier. 



CORN SHELLERS. 



191 



Fig. 215. 




Chum worked by dog-potucr. 

Corn Shellers arc made for both hand and horse- 
power. One of the most convenient and compact hand 
machines is BurralVs, made of iron, furnished with a fly- 
wheel to equalize 
velocity, and worked 
by one person while 
another feeds it, one 
ear at a time. Or, one 
person alone will turn 
it with one hand, while 
the ears are dropped 
in with the other. 
Several other good 
corn shellers are made 
mostly of wood. 

Fig. 217 represents 
a sheller, mostly of 
cast iron, driven by 
horses, by means of BurraCTs Corn Shdler. 

the band partly seen in the cut. The corn in the ear is 
thrown into the hopper at one end, and is separated from 




192 



MECHANICS. 



the cob by rows of teeth revolving in a concave bed and 

Fig. 817. 




Horse-power Corn Shelter. 
set spirally, thus carrying the cobs along and ejecting 
them from the opposite end. 

For shelling corn in large quantities, powerful machines 
driven by horses or steam are required. An excellent 
sheller for this purpose is made by Richards, of Chicago. 
The corn is shoveled directly from the wagon or crib in- 
to the hopper, and requires no extra feeders, or hands, 
to keep the machine from choking. It is built wholly 

of iron, combining 
strength and dura- 
bility. The shellers 
are made of difFerent 
sizes requiring from 
two to twelve horse- 
power. The former 
will shell one bushel, 
ffichards' Com Shelter. an d the latter ten 

bushels per minute. The cost varies from $175 to $475. 
The following is a description of the working part. 

The shelling cylinder is made of heavy rods of wrought 
iron, placed equidistant, presenting a corrugated surface, 
which cannot wear smooth. "Within this, a revolving iron 




Richard's corn sheller. 193 

cylinder, with chilled teeth, thrashes the corn against the 
surfaces of the rod cylinder. The teeth approach the 
rods sufficiently close to keep every ear in rapid motion, 
shelling one ear or one bushel with the same facility. A 
regulator at the discharge end places the machine within 
control of the operator. The spaces between the rods 
allow the shelled corn to escape freely, thus lessening the 
draught, relieving the cylinder from clogging and from all 
liability to cut or grind the grain. 

The cleaner consists of a cylindrical screen revolving 
around the whole length of the sheller, and extending be- 
yond it. A heavy fan blast passes directly through this 
screen, and under it, subjecting the corn to two separate 
cleanings, and delivering it in good condition for market. 
The cleaned corn discharges upon either side desired, and 
the cobs are delivered with the dust at the end of the ma- 
chine. 

ARCHIMEDEAN ROOT-WASHER. 

The spiral principle has been successfully applied in the 
Archimedean Root-washer, (fig. 219.) The roots to be 

Fia 219. 




CroskiWs Archimedean Root-washer. 

Washed are first delivered into a hopper, from which they 

9 



194 



MECHANICS. 



pass into an inclined cylinder made of strips of wood with 
grate-like openings. The cylinder has two portions sepa- 
rated by a partition, in the first of which they remain 
while the handle is turned for washing them. As soon as 
the washing is finished, the motion of the handle is re- 
versed, which throws them into the other part, which has 
a spiral partition, along which they pass until they drop 
into a spout outside. 

BOOT SLICERS. 

These are mostly worked by hand. Out of a large 
number of inventions for this purpose, two are here rep- 
resented; — Wellington's, made of iron, the knives being 

Pig. 221. 



Ficr. 220 




Wellington's Boot Cutter. Boot Cutter of Wood. 

on a revolving cone within the hopper, and shown below 
the machine ; the other of wood, with the knives on the 
face of an iron wheel, which forms one side of the hopper. 
These two machines will cut roots at the rate of about a 
bushel per minute. 



VARIOUS KIXDS OF FARM! MILLS. 



195 



Fig. 222. 



FARM MILLS. 

• 

These are made of iron, and with burr-stones. The 
former are cheaper, and answer a good purpose for grind- 
ing feed for domestic animals. The latter may be also 
used for grinding flour. 

Figure 222 represents an iron farm mill manufactured 
by R. H. Allen & Co., of New York. The grinding sur- 
faces are of chilled iron, 
so arranged as to be 
self-sharpening, and to 
last a long time without 
repairs. When necessary, 
new plates are readily 
inserted. The mill is 
driven by horse or other 
power, the band from 
which is seen in the cut. 
It will grind from five to 
ten bushels per hour, 
varying with the fineness 
of the meal and the 
amount of driving pow- 




Fig. 223. 



Allen's Horse Mill. 

er. A two-horse railway power may be used to advantage. 

This mill is about three feet 
square, four feet high, and 
weighs three hundred pounds. 
Several other iron mills of a 
similar character are made by 
difFerent manufacturers, and 
usually cost about $50. 

Amonsj the burr-stone farm 
,mills, one of the best, most 
compact, and most substan- 
tial, is Forsmaii's^ of Chicago, 
It will be perceived from this 




Forsmmi's Mill. 



represented by fig. 223. 



19G 



MECHANICS. 



figure that the spindle is horizontal, and the face of the 
stones vertical. The frame is of iron. The diameters of 
the stones vary from sixteen to thirty inches, and the 
weight from 400 to 1,500 lbs. The smaller size may be 
run with a power of one to four horses ; the larger, with 
that of ten to thirty horses. Prices 8150 to $375. The 
manufacturers claim that it will grind from one and a 
half to three bushels j:>er hour, for each horse-power used 
in driving it. 

THE COTTON GIN. 



Since the invention of the Cotton Gin by Eli Whitney, 
great improvements have been made, by which the cotton 
is cleaned with great rapidity and in a perfect manner. 



Fig. 224. 




Emery's Cotton Gin— Section. 

The machine manufactured by H. L. Emery, of Albany," 
is one of the best for this purpose. It is represented in 
section in fig. 224. The hopper, at the right, is furnished 
with what is termed a Picker Moll Svpporter, which re- 
volves within the hopper, in the direction shown by the 
arrow, and prevents the cotton from becoming packed. It 



emeey's cotton gust. 



197 



is then taken by the teeth of the saw cylinder, which re- 
duce the cotton to a fine condition. These teeth are 
swept by the brush cylinder, which, running in the same 
direction with the teeth, and slightly faster, carries the 
cotton off from them. Fig. 225 represents the operation, 
the seed escaping from the bottom of the hopper and the 

Fiff. 225. 




Emery's Cotton Gin, with Condenser. 

cotton thrown to the rear into the condenser, which fin- 
ishes the cleaning process and packs or condenses the lint 
cotton within a limited space. The arrows shown in the 
section indicate the direction of the revolutions of the 
picker, saws, and brush cylinder, and also the course 
which the cotton takes in passing through the gin and 
condenser. 



PART II. 

MACHINERY IN CONNECTION WITH WATER. 

GENERAL PRINCIPLES. 

Htdeostatics * treats of the weight and pressure of 
liquids when not in motion ; Hydraulics^ of liquids in 
motion, as, conducting water through pipes, raising it by- 
pumps, etc.; and Hydrodynamics J includes both, by- 
treating of the forces of the liquids, whether at rest or in 
motion. 

CHAPTER I. 

HYDROSTATICS. 
UPWARD PRESSURE. 

A remarkable property of liquids is their pressure in 
all directions. If we place a solid body, as a stone, in a 
vessel, its weight will only press upon the bottom ; but if 
we pour in water, the water will not only press upon the 
bottom, but against the sides. For, bore a hole in the 
side, and the side pressure will drive out the water in a 
stream ; or bore small holes in the sides and bottom of 
a tight wooden box, stopping them with plugs ; then press 
this box, empty, bottom downward, into water, allowing 
none to run in at the top. Now draw one of the side 
plugs, and the water will be immediately driven into the 



* From two Greek words, hudor, water, and statos, standing, or at rest, 
t From two Greek words, hudor, water, and aulos, a pipe. 
t From two Greek words, hudor, water, dunamis, power. 
198 



UPWARD PRESSURE OF LIQUIDS. 199 

box by the pressure outside. If a bottom plug be drawn, 
the water will immediately spout up into the box, show- 
ing the pressure upward against the bottom. Hence the 
pressure in all directions^ upward, sideways, and down- 
ward, is proved. 

The upward pressure of liquids may be shown by pour- 
ing into one end of a tube, bent in the shape of the letter 
U, enough water to partly fill it ; the upward pressure will 
drive the water up the other side until the two sides are 
level. 

On this principle depends the art of conveying water 
in pipes under ground, across valleys. The water will 
rise as high on the opposite side the valley as the spring 
which supplies it. The ancient Romans, who were unac- 
quainted with the manufacture of strong cast-iron pipes, 
conveyed water on lofty aqueducts of costly masonry, 
built level across the valleys. Even at the present day, 
it has been deemed safest to build level aqueducts for con- 
veying great bodies of water, as in very large pipes the 
pressure would be enormous, and might result in violent 
explosions. 

If the valleys are deep, the pipes must be correspond- 
ingly strong, because, the higher the head of water, the 
greater is the pressure. For the same reason, dams and 
large cisterns should be strongest at bottom. Reservoirs 
made in the form of large tubs require the lower hoops to 
be many times stronger or more numerous than the upper. 

MEASUREMENT OP PRESSURE AT DIFFERENT HEIGHTS. 

The amount of pressure which any given height of wa- 
ter exerts upon a surface below may be understood by 
the following simple calculation : 

If there be a tube one inch square (with a closed end), 
half a pound of water poured into it will fill it to a height 



200 



MACHINERY IN CONNECTION WITH WATER. 



of fourteen inches ;* one pound will fill it twenty-eight 



Fi£. 226. 



2 lbs. 5Q5n. 






iy2.lbs.Alin, 



lib 28 in. 



inches; two pounds, fifty-six inches; 
ten pounds, twenty-three feet ; twenty 
pounds, forty-six feet, and so on. 
Now, as the side pressure is the same 
as the pressure downward for the 
same head of water, the same column 
will, of course, exert an equal pressure 
on a square inch of the side of the 
tube. Or, if the tube be bent, as 
shown in the annexed figure (fig. 
226), the pressure upward on the end 
of the tube, at a, will be the same for 
the various heights. 

Now, as the pressure of a column 
fifty feet high is about twenty-two 
pounds on a square inch, the pressure 
on the four sides is equal to eighty- 
eight pounds for one inch in length. 
Hence the reason that considerable 
strength is required in tubes which 

have much head of water, to prevent their being torn 

open by its force. 



yfelb-ldin. 




DETERMINING THE STRENGTH OE PIPES. 



The question may now arise, and it is a very important 
one, How thick must be a lead tube of this size to prevent 
danger of bursting with a head of fifty feet, or of any 
other height ? To answer it, let us turn to the table of 
the Strength of Materials in a former part of this work, 
where we find that a bar of cast lead one-fourth of an 
inch square will bear a weight of fifty-five pounds. If the 



* This is nearly correct, for a cubic foot (or 1,728 cubic inches) of 
water weighs 62 lbs. Consequently, one pound will be 27.9 cubic inch- 
es, and will fill the tube nearly 28 inches high. 



CALCULATING TIIE STRENGTH OF TUBES. 201 

tube be only one-sixteenth of an inch thick, one inch of 
one of its sides will possess an equal strength, that is, 
will bear fifty-five pounds only, and the tube would conse- 
quently burst with fifty feet head. If one-tenth of an 
inch thick, the tube would just bear the pressure, and, to 
be safe, should be about twice as thick, or one-fifth of an 
inch. Half this thickness would be sufficient for twenty- 
five feet of water, and would require to be doubled for 
one hundred feet. A round tube, one inch in diameter, 
having less surface to its sides, would be about one-third 
stronger. A tube twice the diameter would need twice 
the thickness ; or if less in diameter, a proportionate de- 
crease in thickness might take place. If, instead of cast 
lead, milled lead were used, the tube would be nearly four 
times as strong, according to the table of the strength of 
materials already referred to. 

SPRINGS AND ARTESIAN WELLS 

result from the upward pressure of water. Rocks are 
usually arranged in inclined layers (fig. 227), and when 

Fig. 22?. 




rain falls upon the surface, as at c d, it sinks down in the 
more porous parts between these layers, to c. If the lay- 
ers happen to be broken in any place below, the water 
finds its way up through the crevices by the pressure of 
the head above, and forms springs. If there are no open- 
ings through the rocks, deep borings are sometimes made 
9* 



202 



MACHINERY IX CONNECTION WITH WATER. 



artificially, through which the water is driven up to the 
surface, as at <?, forming what are termed Artesian Wells. 
The head of water which supplies them may be many 
miles distant, the place of discharge being on a lower 
level. It has sometimes been found necessary to bore 
more than a thousand feet downward before obtaining 
water which will flow out freely at the surface of the earth. 



ifi 




1=4=1 




1=1=== 






= —< 




DETERMINING THE PRESSURE ON GIVEN SURFACES. 

The pressure of liquids upon any given surface is always 
exactly in proportion to the height, no matter what the 
Fig. 228. shape of the vessel may be. If, 

for instance, the vessel a (fig. 
228), be one inch in diameter, 
and the vessel b be three inches 
in diameter, the water being 
equally high in both, the press- 
ure on the whole bottom of b 
will be nine times as great as on 
the bottom of a ; or any one inch of the bottom of b will 
receive as great a pressure as the bottom of a. Again, if 
the vessel c, broad at the top, be narrowed to only an 
inch in diameter at bottom, the press- Fig. 229. 

tire upon that inch will still be the 
same, most of the weight of its con- 
tents resting against the sides, d d. 
If the vessel, A (fig. 229), be filled 
with water to a height of fourteen 
inches, the pressure will be half a 
pound on every square inch of the 
bottom, or upon every square inch 
of the sides fourteen inches below the surface. If the 
tube, C, be an inch square, the water will be driven into 
it with a force of half a pound, and will press with that 
force against the one-inch surface of the stop-cock, C. If 




A PUZZLE EXPLAINED. 



203 



the tube, B, be now filled to an equal height, the same 
force will be exerted against the other side. To prove 
this, let the stop-cock be opened, when the two columns 
of water will remain at an exact level. 

If enough water be now poured into the tube, B, to fill 
if to the top, it will immediately settle down on a level 
with the water in A, raising the whole surface in the lat- 
ter. This result has seemed strange to many, who can 
not conceive how a small column of water can be made to 
balance a large one, and it has been therefore termed the 
Hydrostatic Paradox. But the difficulty entirely vanish- 
es, and ceases to appear a paradox, when we remember 
that the water in the larger vessel rises as much more 
slowly than it descends in the smaller, as the large one 
exceeds the smaller ; thus acting on the principle of vir- 
tual velocities in precisely the same manner that a heavy 
weight on the short end of a lever is upheld by a small 
weight on the long end. The great mass of water is sup- 
ported directly by the bottom of A, in the same way that 
nearly all the weight on the lever is supported by the 
Fig. 230. fulcrum. A man who was seeking a solu- 

tion to the absurd mechanical problem of 
perpetual motion, and who supposed that 
the large mass in A would overbalance the 
small column in B, and drive it upward, 
constructed a vessel in the form shown in 
fig. 230, so that the small column, when 
forced upward, would flow back into the 
larger vessel perpetually.. He was, how- 
'Motion.' ever, greatly surprised to see the fluid in 
both divisions settle at the same level. 

This principle may bo further explained by the following 
experiment : A B (fig.231) represents the inside of a metallic 
vessel, with a bottom, C, which slides up and down, water- 
tight. If water be poured in to fill the lower or larger 
part only, it will be found to j^ress on the sliding bottom 




Attempted Perpetual 



204 



MACHINERY IN CONNECTION WITH WATER. 




with a force exactly equal to its own weight ; that is, if 
there is a pound of water, it will press on the bottom with 
a force equal to one pound. Now, if the bottom be pushed 
rig. 231. upward, so as to drive the water into the 

narrow part of the vessel, the pressure upon 
the bottom becomes instantly much greater, 
or equal to many pounds, the water being 
the same in quantity, but with a much 
higher head than before. Suppose the nar- 
row part of the vessel is twenty times 
smaller than the larger part, then, in pushing 
the bottom up one inch, the water is driven 
twenty inches upward in the tube. So then, 
according to the rule of virtual velocities, it will require 
twenty times the force, because it moves upward twenty 
times faster.* This, then, is precisely similar to the in- 
stance where a pound on the longer end of a steelyard 
balances twenty pounds on the shorter ris# 232# 

end. In this instance, the upper parts, <gH^0 

T) D, of the vessel operate as the fulcrum 
of a lever, and offer resistance to the slid- 
ing part as soon as the water begins to 
ascend the tube. ^ 

HYDROSTATIC BELLOWS. 

This principle is shown in the Hy- 
drostatic Bellows (fig. 232), which con- 
sists Of tWO round pieces Of board, Hydrostatic Bellows. 

connected by a narrow strip of strong leather ; into it is 
inserted a long, narrow tube, B, with a small funnel, e, at 
the top. When water is poured into this tube, it will 
raise a weight as much greater than the weight of the 




* The pressure will be as great upon tue bottom as if tlie vessel con- 
tinued a uniform size all tue way up. 



HYDEOSTATIC PKESS. 205 

water in the tube as the surface of the upper board ex- 
ceeds the cross-section of the tube. Thus, if a pound of 
water fills a tube half an inch in diameter, and the bellows 
are two feet in diameter, then this pound will raise more 
than two thousand pounds on the bellows (if it be strong 
enough), because the surface of the bellows is more than 
two thousand times greater. 

In the same way, a strong, iron-bound hogshead may 
be burst with the weight of a single gallon of water by 
pouring it into a long and narrow tube set upright in 
the bung of the filled hogshead. If, for instance, the inner 
surface of the hogshead be 20 square feet, or 2,880 square 
inches, a tube of water 23 feet high will press with a force 
of 10 pounds on every square inch, or equal to a force of 
28,800 pounds, or 14 tons, on the whole surface. 

HYDEOSTATIC PEESS. 

The Hydrostatic Press owes its extraordinary power to 
a similar principle ; but, instead of a bellows, there is a 
moving piston in a strong metallic cylinder ; and instead 
of being worked by the mere weight of the water, it is 
driven into the cylinder by means of the lever of a pow- 
erful forcing-pump. An instrument of this sort, possess- 
ing enormous power, was used to elevate the great tubular 
iron bridge in England. It was found necessary to make 
the sides of the cylinder into which the water was driven 
no less than eleven inches thick, of solid iron ; and so 
great was the pressure given to the confined water, as 
to have forced it up through a tube higher than the 
summit of Mont Blanc. I'n the port of New York, ves- 
sels of a thousand tons' burden have been lifted by the 
hydrostatic press. 

This machine has been applied in compressing hay, cot- 
ton, and other bulky substances into a compact form, so 
that they may occupy but little space, for conveyance to 



206 



MACHINERY IN CONNECTION WITH WATER. 



distant markets. The following figure (fig. 233) exhibits 
the different parts of this powerful machine. A is a cis- 
tern to supply water, which is raised by working the han- 
dle, B, of the forcing-pump ; the water passes through the 
valve, C, opening upward, and through the spring valve, 

Fig. 233. 




Hydrostatic Press. 



D, opening toward the large cylinder, E. Being thus 
driven into the space, E, it raises the piston, F, and exerts 
a prodigious pressure upon the mass of hay or cotton, G. 
The piston is lowered by turning the screw, H, which al- 
lows the water to pass back into the cistern at I. In the 
figure the hay or cotton is shown as visible to the sight, 
in order to represent the whole more plainly ; but in prac- 
tice it is thrown into a square box or chamber of strong 
plank, of the size of the intended bundle. One side is 



HYDROSTATIC PEESS. 20? 

hung upon stout hinges, and is opened for the removal of 
the bale when the pressing is completed. 

To estimate the power of this machine, divide the 
square of the diameter of the piston, F, by the square of 
the diameter of the piston of the forcing-pump, and multi- 
ply the quotient by the power of the lever, B. For ex- 
ample, suppose the piston, F, is 16 inches in diameter, and 
the piston of the forcing-pump is 2 inches in diameter. 
The square of 16 is 256 ; divide this by 4, the square 
of 2, and the result will be 64. If the lever, B, increases 
the power five times, the whole power of the machine will 
be 320; that is, a force of one pound applied to the lever 
will raise the large piston with a force equal to 320 pounds ; 
or, if a force of 100 pounds be given to the lever, the 
power will be 32,000 pounds, or 16 tons. Reducing the 
diameter of the smaller piston to half an inch, and in- 
creasing the force of the lever to twenty times, the whole 
power exerted will be thirty-two times as great, or equal 
to 960 tons. In ordinary practice, it is more convenient 
and economical to reduce the diameter of the larger piston 
to a few inches only, making the forcing-pump correspond- 
ingly small, the power depending entirely on the dispro- 
portion between them. Such presses may be worked rap- 
idly by horse, water, or steam power. 

One great advantage which the hydrostatic press pos- 
sesses over those worked by screws results from the little 
friction among liquids, nearly the only friction existing in 
the whole machine being that of the two pistons, which is 
comparatively small. Another is the smallness of the 
compass within which the whole is comprised ; for a man 
might, with one not larger than a tea-pot, standing before 
him on a table, cut through a thick bar of iron with as 
much ease as he could chip pasteboard with a pair of 
shears. 



208 



MACHINERY IN CONNECTION WITH WATER. 



SPECIFIC GRAVITIES. 



Fig. 2*4. 



In connection with Hydrostatics, the subject of the 
specific gravities of bodies is one of importance. The 
specific gravity of a substance is its comparative weight 
with some other substance, an equal bulk of each being 
taken. Water is usually the standard for comparison. 

To ascertain the specific gravity, weigh the body both 
in and out of water, and observe 
the difference; then divide the 
whole weight by this difference, and 
the quotient will be the specific 
gravity sought. For example, if a 
stone weighs 12 lbs. out of water 
and 7 lbs. in water, divide 12 by 
5, and the quotient is 2.4, which 
shows that the stone is 2 4 | J0 times 
heavier than water. Figure 234 
shows the mode of weighing the 
body in water, by suspending it be- 
neath a balance on a hair or thread. 

It was in a similar way that Archimedes is said to have 
succeeded in detecting the suspected fraud in the manu- 
facture of the golden crown of the ancient king of Syra- 
cuse. He first weighed it, and then found that it dis- 
placed more water when plunged in a vessel just filled, 
than a piece of pure gold, and also that it displaced less 
than silver, whence he inferred the mixture of these two 
metals. 

When the specific gravity of a substance lighter than 
water is to be ascertained, it is loaded down by a weight, 
so as to sink in water, for which allowance is made in the 
calculation. A very simple way to determine this in dif- 
ferent kinds of wood is to form them into rods or sticks 
of uniform size throughout, and then to observe what 
portion of them sink when placed endwise in water. 




Instrument for taking Specific 
Gravities. 



TABLE OF SPECIFIC GRAVITIES. 



209 



A knowledge of the specific gravities of various sub- 
stances becomes useful in many ways, among which is 
ascertaining the weight of any structure, machine, or im- 
plement, by knowing that of the material used in its man- 
ufacture ; determining the cost, by the pound, of such 
material ; or knowing the bulk or size of any load for a 
team. The latter may often be of great use in ordinary 
practice, by enabling the teamster to calculate beforehand 
the amount of load to give his horses, whether in timber, 
plank, brick, lime, sand, or iron, without first subjecting 
them to overstraining exertions in consequence of error in 
random guessing. 

Tables of specific gravities, for this purpose, and weights 
of a cubic foot of different substances, are here given. 



TABLE OP SPECIFIC GRAVITIES. 



Metals. 



Gold, pure. 19.36 

" standard 17.16 

Mercury 13.58 

Lead 11.35 

Silver 10.50 

Copper 8.83 Zinc 



Iron 7.78 

" cast 7.20 

Steel 7.82 

Brass, common 7.82 

Tin 7.29 

6.86 



Stones and Earths. 



Brick 1.90 

Chalk 2.25 to 2.66 

Clay 1.93 

Coal, anthracite, about 1.53 

Coal, bituminous 1.27 

Charcoal 44 

Earth, loose, about .' 1.50 

Flint 2.58 

Granite, about 2.65 



Gypsum 1.87 to 2.17 

Limestone 2.38 to 3.17 

Lime, quick 80 

Marble 2.56 to 2.69 

Peat 60 to 1.32 

Salt, common 2.13 

Sand 1.80 

Slate 2.67 



Woods — dry. 

Green wood often loses one-third of its weight by seasoning, and 
sometimes more. The same kind varies in compactness with soil, 
growth, exposure, and age of the trees. 



210 



MACHINERY IN CONNECTION WITH WATER. 



Apple 68 to .79 

Ash, -white 73 to .84 

Beech - 73 to .85 

Box 91 to 1.32 

Cherry 71 

Cork .21 

Elm 58 to .67 

Hickory 84 to 1.00 

Maple 65 to .75 

Pine, white 47 to .56 



Pine, yellow 55 to .66 

Oak, English 93 to 1.17 

" white 85 

" live 94tol.l2 

Poplar, Lombardy 40 

Pear 66 

Plum 78 

Sassafras 48 

Walnut 67 

i Willow 58 



Miscellaneoits. 



Beeswax 96 

Butter 94 

Hone)' 1.45 

Lard 94 

Milk 1.03 

Oil, linseed 94 



Oil, whale 92 

" turpentine 87 

Sea water 1.02 

Sugar 1.60 

Tallow 93 

Vinegar 1.01 to 1.08 



Weights of a Cubic Foot of various Substances, from which the Bulk of a 
Load of one Ton may be easily calculated. 

Cast Iron 450 pounds. 

Water 62 

White pine, seasoned, about 30 

White oak, " " 52 

Loose earth, about 95 

Common soil, compact, about 124 

Clay, about 135 

Clay with stones, about 160 

Brick, about 125 

Bulk of a Ton of different Substances. 

23 cubic feet of sand, 18 cubic feet of earth, or 17 cubic feet of clay, 
make a ton. 18 cubic feet of gravel or earth before digging make 27 
cubic feet when dug ; or the bulk is increased as three to two. There- 
fore, in filling a drain two feet deep above the tile or stones, the earth 
should be heaped up a foot above the surface, to settle even with it, 
when the earth is shoveled loosely in. A cubic foot of solid half-rotted 
manure weighs about 56 lbs., requiring about 36 cubic feet to the ton. If 
coarse or dry, more will be required. Hay varies much in specific grav- 
ity with the kind, and the degree of pressure in the bay or stack ; but 
good timothy hay, under medium pressure, requires about 500 cubic 
feet to the ton ; clover, variable, — about one-half more. 



VELOCITT OF WATEK. 211 

CHAPTER n. 

HYDRAULICS. 
VELOCITY. OP FALLING WATEK. 

Liquids in motion are subject to the same laws as solids 
in motion. Falling water increases in velocity at the 
same rate that the motion of falling solids is accelerated, 
as already explained under the head of Gravitation. Thus 
a perpendicular stream of water descends one foot in a 
quarter of a second, four feet in half a second, nine 
feet in three-fourths of a second, and sixteen feet in one 
second. Like falling solids, the velocity at the end of 
the first quarter will be eight feet per second ; at the end 
of the second quarter, sixteen feet; at the end of the third 
quarter, twenty-four feet ; and at the end of the fourth 
quarter, thirty-two feet per second. 

Now, if there be an orifice made in the side of a vessel 
of water, the water will spout out with the same swiftness 
as if it fell perpendicularly from an equal height, were it 
not retarded a little by friction. For example, if the 
head of water is one foot above the orifice, the velocity 
would be at the rate of eight feet per second, but for fric- 
tion, which reduces it to about five and a half feet. The 
velocity for any other height of head may be easily found 
by deducting the same proportionate rate from the veloc- 
ity of a falling body. Thus, for example, if the head be 
sixteen feet, the speed would be thirty-two feet (as shown 
under Gravitation), from which, deducting the friction, 
the real velocity would be about twenty-two feet per 
second. 

It has been already shown that the velocity of a falling 
body increases at the same rate as the increase in the time 
of falling ; for instance, the speed is twice as great in two 
seconds as in one ; three times as great in three seconds ; 



212 



MACHINERY IN CONNECTION WITH WATER. 



four times as great in four seconds, and so on. But the 
distance fallen through increases as the square of the time ; 
that is, it is four times as great in two seconds, nine times 
as great in three seconds, sixteen times as great in four 
seconds, etc. Thus we see that, jn order to produce a 
twofold velocity, a fourfold height is necessary, etc. So 
also in the escape of water under a head : to double the 
velocity of the stream, the head must be four times as 
high ; to triple it, the head must be nine times as high, etc. 

DISCHARGE OF WATER THROUGH ORIFICES AND PIPES. 



Fig. 235. 



Fig. 236. 



Fig. 237. 



The discharge of water from a vessel is greatly influ- 
enced by the nature of the orifice through which it flows. 

If, for example, a 
vessel or cistern 
have a thin bottom 
of tin, with a 
smooth, circular 
hole, we might natu- 
rally suppose that 
the discharge would 
be as easy as it 
could be made, and 
that water would 
pass as rapidly 
through it as 
through any orifice 
of an equal size. But this is not the fact. 
As the particles approach this orifice, their 
motion throws them across, and they 
partly obstruct the opening; it will be 
seen that they converge toward a point 
just under the orifice, where the stream will be consider- 
ably contracted (Fig. 235). If a short tube be inserted 
into the hole (the head being the same), this crossing of 




DISCHARGE OF WATER THROUGH PIPES. 213 

particles will be partly prevented, and the liquid will flow 
more rapidly. The greatest effect is produced when the 
tube is twice as long as its diameter (fig. 236). If the 
tube be enlarged at its upper and lower end, similar to the 
form of the contracted stream of water in fig. 237, the 
quantity discharged is greatly increased. 

When water flows down an inclined plane, the same law 
applies as to the motion of a solid body rolling down a 
plane. The velocity increases as the square of the distance, 
and is the same as the velocity of a body falling freely 
downward from a height equal to the perpendicular height 
of the plane. Unless the stream, however, is very large, 
its speed is quickly diminished by the friction of its chan- 
nel,* until this friction becomes as great as the descending 
force, after which the motion becomes uniform. Hence 
the reason that large streams, with an equal degree of de- 
scent, flow so much more rapidly than small ones, the 
gravitating force being so much greater that friction has 
a less retarding effect upon them. 

In pipes which wholly surround the flowing stream, the 
friction becomes still greater, and the difficulty is only ob- 
viated by making the pipe of larger dimensions than 
would otherwise be necessary, so as to allow a free passage 
of a sufficient quantity of water through the centre of the 
tube, while a ring or hollow cylinder of water is nearly at 
rest all around it. The tables in the Appendix exhibit 
this decreased velocity in tubes of various sizes. 

Lead pipes, for conveying the water of springs under- 
ground, should commonly be three-fourths of an inch in 
diameter. Five-eighths will answer where the distance is 
short and the descent considerable. But with a half-inch 
pipe, the friction of the sides is so great, compared with 
the small force of the current, that but little water will 
flow through it. 



* Which increases as the square of the velocity. 



214 MACHINERY IN CONNECTION WITH WATER. 



VELOCITY OF WATER IN DITCHES. 

It is often of great practical utility to know what 
amount of water may be carried off in draining, or sup- 
plied in irrigation, by channels of any given size and 
descent. The following rule will apply to all cases, from 
the plow-furrow to the mill-race, or even to the large 
river, and may be used by any boy who understands 
common arithmetic, and which is illustrated and made 
plain by the example that follows the rule. 

To ascertain the mean (or average) velocity of water in 
a straight channel of equal size throughout : 

Let j^the fall in two miles in inches ; 

Let d=th.e hydraulic mean depth ; 

Let -y=the velocity in inches per second ; 
then the rule is thus expressed : v=0.91 \/fd, or, in plain 
words, the velocity is equal to the hydraulic mean depth, 
multiplied by the fall, with the square root of this prod- 
uct extracted, and then multiplied by 0.91. 

The " hydraulic mean depth-" is found by dividing the 
cross-section of the channel by the perimeter, or border. 
The perimeter is the aggregate breadths of the sides and 
bottom of the channel. 

The rule will be rendered quite plain by an example. 
Suppose a smooth furrow is cut six inches wide and four 
inches deep, with perpendicular sides, and that it descends 
one inch in a rod ; to find the quantity of water that will 
flow through it. One inch fall in a rod is 320 inches in a 
mile, or 640 in two miles. The perimeter in contact with 
the water will be six inches on the bottom and four 
inches in each side = 14 inches. The area of the cross- 
section will be six times 4 = 24, which, divided by 14, 
the perimeter, gives 1.7 = the hydraulic mean depth. 
Then, by applying the preceding rule : 

v =0.91 V 640 x 1.7, or v=0.91 x 33=30 inches, is the ve- 



LEVELING INSTRUMENTS. 215 

locity per second, which -would be about three gallons per 
second, or three hogsheads per minute. 

An open ditch, therefore, with smooth sides, conveying 
a stream of this size, would carry off, in one hour, from 
an acre of land, all the water which might fall by half an 
inch of rain, during the wet season ; for half an inch of 
rain would be one hundred and eighty hogsheads per 
acre, which would pass off in one hour ; or it would sup- 
ply in one hour, by the process of irrigation, as much 
water as a heavy shower of half an inch. Where the 
descent is greater, the increased quantity may be readily 
calculated by the rule given. The capacity of smooth- 
sided underground channels may be determined in the 
same way ; but if built of rough stones, great allowance 
must be made, as they will retard the flow of water. 

In common practice, too, even with straight, open 
ditches, the velocity will be much diminished by the 
rough sides. 

LEVELING INSTRUMENTS. 

The simplest mode of leveling, or ascertaining the slope 
for ditches, is to cut a few yards of the ditch, so that wa- 
ter may stand in it, and then to set two sticks perpendicu- 
larly, both rising to an equal height above the surface. 

Fig. 238. 



* Simple Method cf Talcing Levels. 

The sticks should be measured at equal distances from 
the top downward, and marked, and then pressed into 
the earth, till the water reaches the mark. The level may 
then be determined with much accuracy by " sighting " 
over the tops of these sticks. Fig. 238 exhibits this ar- 
rangement. The shorter the sticks, and the longer the 
piece of water, the less will be the liability to error. 



216 



MACHINERY IN CONNECTION WITH WATEE. 



A leveling instrument for general use, sufficiently ac- 
curate for all common purposes, may be made in the fol- 
lowing manner : — Pro- 



■jjgh 



Fig. 239. 

a 



I 



i 



^r 



cure a mason s or car- 
penter's spirit-level, (a, 
fig. 239) fasten it to the 
upper side of a straight 
bar of wood, and on the 
ends of this bar secure 
small, upright pieces of 
tin plate, 5, b, having 
openings cut in the 
centre. Horizontally 
across these openings, 
draw very fine wire, 
which shall be exactly 
f at equal heights above 

each end of the bar of wood, to adjust which, one should 
be capable of sliding, and be screwed or wedged to its 
place at pleasure. The bar is placed on a common com- 
pass staff, as shown in 
the cut, turning at the 
ball and socket, below 
the spirit level. A tripod 
(fig. 240) is better, if it 
can be had. A small 
spirit-level should be se- 
cured across the bar, so 
that it may be adjusted 
both ways. When the 
bar is made perfectly 
level, as shown by the air-bubble, by sighting through at 
the two wires, the levelness or descent of the land may be 
determined. 

To ascertain whether these threads are both of equal 
heights above the bar, let a mark be made where they in- 



Fig. 240. 




ARCHIMEDEAN SCREW. 



21? 



tersect some distant object ; then reverse the instrument, 
or turn it end for end., and observe whether the threads 
cross the same mark. If they do, the instrument is cor- 
rect ; but if they do not, then one of the sights must be 
raised or lowered until it becomes so. 

In laying out canals and rail-roads, where extreme ac- 
curacy is needed, the spirit-level, attached to a telescope, 
is used. So great is the perfection of this instrument, 
that separate lines of levels have been run with it for six- 
ty miles, without varying two-thirds of an inch for the 
whole distance. 

The use of a cheap and simple instrument to determine 
the position and descent of ditches with ease and preci- 
sion, before commencing with the spade, will save a vast 
amount of the trouble and expense which those often 
meet with whose only method is to " cut cmd try" 

HYDRAULIC MACHINES. 

ARCHIMEDEAN SCREW. 



Machines for raising water are of frequent use on every 
farm. One of the simplest contrivances, in principle, for 
this purpose, is the Screw of Archimedes. It may be 



Fig. 241. 




The Screw of Archimedes 

easily made by winding a lead tube around a wooden 
cylinder or rod (fig. 241), in the form of a screw. 
1Q 



When 



218 



MACHINERY IN CONNECTION WITH WATER. 



placed iii an inclined position, with one end in water, and 
made to revolve, the water resting at the lower side of 
each turn of the screw is gradually carried from one end 
to the other, and discharged at the upper extremity. Its 
simplicity and small liability to get out of order render 
the Archimedean screw sometimes useful where water is 
to be raised from an open stream to a short distance, as 
for irrigation, the motion being easily imparted to it by 
means of a small water-wheel, driven by the stream. 



PUMPS. 



Great improvement has been made in the common 



Tie:. 242. 




Common Pump : b, lower or fixed 
valve, G, piston with valve, a, 
opening upward; D d } piston- 
rod ; F, spout, 



pump for farms within a few years. 
The best cast-iron pumps, made 
almost wholly of this metal, ex- 
ceed in durability and ease of 
working those formerly con- 
structed of wood, and excel others 
in cheapness. Fig. 242 exhibits 
the working of the common pump, 
the water first passing through 
the fixed valve below, and then 
through the one in the piston ; 
both opening upward, it cannot 
flow back without instantly shut- 
ting them. The water is driven 
up by the pressure of the at- 
mosphere, explained in the next 
chapter. 

Fig. 243 is an iron cistern pump, 
showing; the mode of bolting it to 
the floor or platform, and rep- 
resenting, also, its neat and com- 
pact form, occupying but little 
space at one side, or in the corner 
of a kitchen, over the cistern. 



PUMPS. 



219 




Fisr. 244. 



Fig. 244 represents a cistern or well pump, so constructed 
that the working parts are about 20 inches below the plat- 
form, or base of the pump, and it is therefore well adapt- 
ed for outdoor work. If the well 
or cistern is kept covered tight, 
the pump will not freeze below 
the platform. It will succeed 
in any well not over twenty feet 
deep, and by means of its 
various couplings may be made to 
draw water in a horizontal or in- 
clined position, provided the whole 
height is not much over twenty feet. 

Fig. 243. 




Cistern Pump. 



Non-freezing Pump. 



An excellent deep-well pump, made by Cowing & Co., 
of Seneca Falls, N". Y., is represented by fig. 245 ; the 
working part, being placed at the bottom of the well, is 
adapted to any depth of water, the rod working safely 
within the pipe. The lower part of the cylinder is fur- 
nished with a strainer, and is plugged at the bottom, to 



220 MACHINERY IX CONNECTION WITH WATER. 

Fig. 246. Fijr. 245. 





Drive Pump. 

prevent the ingress of sand and i 
mud. The connecting pipe between & 
the cylinder at the bottom and the 
standard at the top is wrought or , 
galvanized iron. The pump, of *$0. 
course, needs bracing, to prevent 
swinging when worked. 

Drive Pumps. — Fig. 246 rep- 
resents the new mode of making 
wells, by simply driving into the 
earth common iron gas-pipe, pointed -jSSljIjfl 
at the lower end, and perforated at x5r?8 
the sides, near the lower extremity, Deep-wen ramp. 



DRIVE PUMPS. 



221 



for the ingress of water — thus obviating entirely the cost 
and labor of digging wells. If driven through a subter- 
ranean spring, a stratum of water, or a wet layer of sand or 
gravel, it is obvious that the water will immediately flow 
through the perforations into the pipe ; and, by attaching a 
good pump to the pipe and pumping for a time, all the par- 
ticles of sand and fine gravel will be drawn out ; and the 
cavity thus formed around the perforations will remain filled 
with pure water. These tubes and pumps are admirably 
adapted to localities where large beds of wet gravel exist 
fifteen or twenty-five feet below ; and, in fact, to all soils 
where large stones are not abundant. Where these occur, 
the pipe must be withdrawn, and tried in a new place, 
until success is attained. 

In the Chain Pump, a partial cross-section of whioh is 



Figr. 247. 



Fie:. 24S. 



Chain Pump 
Section. 




liotary Pump, for Barrels, etc. 
here shown, (fig. 247), the chain is made to revolve rapid- 
ly on the angular wheel by means of a winch attached to 



222 



MACHINERY IN CONNECTION WITH WATEK. 







Fig. 249. 




■TO 




g 


i 


1 11 



the upper one, and being furnished with a regular succes- 
sion of metallic discs, which 
nearly fit the bore in the tube, 
«, the water is carried up in 
large quantities. When the 
motion is discontinued, the 
water settles down again into 
the well, and consequently 
this pump is not liable to 
accident by freezing. By 
sweeping rapidly through the 
water, it preserves it in better 
condition, and prevents stag- 
nation. The friction being 
very small, it will last a long 
time without wearing out. 

Rotary Pumps. — A succes- 
sion of cavities made in the 
exterior of a short cylinder 
receive the water from the 
pump-tube below, and force 
it away into the elevating 
tube. When driven fast, it 
pumps with great rapidity. 
It possesses this advantage 
over the common pump, that 
the motion being continuous, 
no force is lost by repeatedly 
checking the momentum. In 
the figure on the preceding 
page, the pump is represented 
as inserted in a barrel of oil, 
which is to be emptied into 
the reservoir above, and is 
Suction and Forcing-pump. worked by hand. Larger 

rotary pumps are driven by horse and steam power. 




TURBINE WATER-WHEELS. 



223 



Suction and Forcing-Pump. — The accompanying cut (fig. 
249) represents a suction and forcing-pump combined in one, 
for the purpose of drawing water from a well or cistern, 
and forcing it to tanks in upper stories, or throwing water 
into upper rooms in case of fire. By lengthening the rod, 
the working parts may be placed at the bottom of a deep 
well, and the whole used as a deep well pump. 

TURBINE WATER-WHEELS. 

The large wooden wheels formerly used for the appli- 
cation of water power to mills and other machinery are 
rapidly giving place to iron Turbine wheels. Overshot 
wheels, the best kind formerly employed, were turned by 
the weight of the water, the whole of which was held in 
the slowly descending buckets of the wheel. Turbine 
wheels do not hold the water, but merely receive and im- 
part the force of the rushing current, the water being 
held by the flume above. Hence, a turbine wheel of 
quite small size may impart to machinery nearly the 
whole force of a powerful current of water. 

Turbine wheels are placed in a horizontal position, with 

vertical axes. Being 
under water, they never 
freeze ; and they are not 
impeded by back-water 
when a flood occurs. 
There are two principal 
kinds among those in 
common use, — those, 
like the Reynolds wheel, 
which have a single 
opening at the side, 
through which the wa- 
ter is admitted; and such as the Leffel and Van de Water 
wheels, into which the water is admitted through several 
openings around them. 



Fisr. 250. 




Section of Reynolds' Wieel. 



224 



MACHINERY IX CONNECTION WITH "WATER. 



Fig. 252. 




View of Reynolds' Turbine =S? 
Wheel. 



Fig. 250 is a section of the Reynolds wheel ; (r, the 
Fig. 251. gate for admitting the 

water through the hori- 
zontal shute from the 
flume ; A, A, the circu- 
lar passage for the water, 
which is gradually di- 
minished in volume as it 
strikes the buckets or 
blades, B,B^ and escapes 
through the bottom and 
top of the wheel. The 
arrows show the currents, and the curved dotted lines the 
openings through which the Fig. 253. 

water escapes — the curved 
arrows exhibiting the re- 
bounding of the current 
against the blades, before 
passing out through the is- 
sues. Fig. 251 is an exterior 
view of the wheel, showing 
the gate for the admission 
of the water ; and fig. 252 

represents the shaft and 

Fig. 254. Section of Van de Water Wheel. 

buckets separate. 

Fig. 253 is a section of 
the Yan de Water wheel, 
6r, 6r, 6r, 6r, being the 
gates for admitting wa- 
ter, and J?, _Z?, the buck- 
ets — the arrows rep- 
resenting the entering 
currents. H shows, by 
dotted lines, the position 
Van de Water wheel. of one of the gates when 

closed. The water, after entering the buckets, passes out 





TURBINE WATER-WHEELS. 225 

below, where the blades are curved backwards, to receive 
all the force of the escaping water. Fig. 254 is a view of 
this wheel, showing the admission gates, and the wheel at 
the top, for opening and shutting the gates at one movement. 

The Reynolds wheel is placed under water, outside the 
flume, and the current admitted at the side, as already 
stated. The Van de Water wheel is placed within, and 
on the bottom of the flume, in the floor of which a circu- 
lar hole is cut, through which the water escapes. Both 
are excellent wheels, and are among those most exten- 
sively manufactured in the country — the former by George 
Tallcot, of New York, and the latter by the inventor, H. 
Van de Water, of Attica, 1ST. Y. 

Turbine wheels, of the best construction, do not lose 
more than one-seventh or one-eighth of the whole descend- 
ing force of the water. Hence, the power of any stream 
may be determined beforehand with much accuracy, if 
the descent or head and the number of cubic feet of wa- 
ter per minute are known. It has been already shown in 
this work, that a single horse-power is equal to lifting 
33,000 lbs. one foot, per minute. This is equivalent to 
raising 530' cubic feet of water to the same height, or 53 
cubic feet, ten feet high. A stream, then, which falls 10 
feet, and discharges 53 cubic feet in a minute, or nearly 1 
per second, has an inherent force of one horse-power. 
Add one-seventh, making it about 60 cubic feet, and we 
have the size of a stream for one horse-power, at ten feet 
fall. Twenty feet descent would double the power, forty, 
quadruple it, and so on; and a similar increase result 
from employing a larger stream. As examples, a small 
wheel, seven or eight inches in diameter, will be sufficient 
for such a purpose. One of this size, with 20 feet head, 
and discharging 70 or 80 cubic feet of water per minute, 
will possess about three horse-power ; and with forty feet 
head, requiring over 100 cubic feet per minute, it will 
have a power of eight or nine horses. 
10* 



226 MACHINERY IN CONNECTION WITH WATER. 

The simple rule given in the second paragraph of the 
present chapter, for determining the velocity of a current 
of water spouting out under any given head, will enable 
any one who understands arithmetic to calculate the 
proper speed of a turbine wheel, which varies with the 
head and the diameter of the wheel. It is found that the 
buckets or blades should move with about two-thirds the ve- 
locity of the current as it rushes from the flume ; hence, 
as an example, under a head of 16 feet, which drives out 
a stream about 22 feet per second, the exterior of the 
turbine wheel should move about 14 or 15 feet per second. 
If 1 foot in diameter, it should therefore revolve five 
times per second ; or, if 2-^- feet in diameter, only twice 
per second. Other examples may be readily computed. 

There are occasional opportunities for employing water 
power for driving farm machinery — as thrashing ma- 
chines, mills for grinding feed, corn shellers, wood saws, 
straw cutters, etc., by bringing streams along hill-sides, 
or over bluffs ; in which cases, turbine wheels would be 
cheaper than steam-engines, and require neither food nor 
fuel. The water of small streams might be saved in dams 
or ponds, giving a power of five or six horses for 
one day in each week for grinding, thrashing, and other 
purposes. 

THE WATER-RAM. 

One of the most ingenious and useful machines for ele- 
vating water is the Water-ram. It might be employed 
with great advantage on many farms, were its principle 
and mode of action more generally understood. By means 
of a small stream, with only a few feet fall, a current of 
water may be driven to an elevation of 50 feet or more 
above, and conveyed on a higher level to pasture-fields 
for irrigation, to cattle-yards for supplying drink to 
domestic animals, or to the kitchens of dwellings for cu- 
linary purposes. 



THE WATER- RAM. 



227 



Fijr. 255. 



Its power depends on the momentum of the stream. 
Its principal parts are the reservoir, or air-chamber, A, 
(fig. 255), the supply pipe, J5, and the discharge pipe, C. 
The running stream rushes down the drive, or supply- 
pipe, _Z?, and, striking the waste valve, i>, closes it. The 
stream being thus suddenly checked, its momentum opens 
the valve, J£, upward, and drives the water into the reser- 
voir, A, until the air within, being compressed into a 
smaller space by its elasticity, bears down upon the water, 
and again closes the valve, E. The water in the supply- 
pipe, _Z?, has, by this 
time, expended its mo- 
mentum, and stopped 
running ; therefore the 
valve, D, drops open 
again, and permits it to 
escape. It recommences 
running, until its force 
again closes the waste 
valve, D, and a second 
portion of water is driven into the reservoir as be- 
fore, and so it repeatedly continues. The great force of 
the compressed air in the reservoir drives the water up 
the discharge-pipe, C, to any required height or distance. 

The mere weight of the water will only cause it to rise 
as high as the fountain head ; but like the momentum of 
a hammer, w T hich drives a nail into a solid beam, which a 
hundred pounds would not do by pressure, the striking 
force of the stream exerts great power. 

The discharge pipe, (7, is usually half an inch in diame-" 
ter, and the supply-pipe should not be less than an inch 
and a fourth. A fall of three or four feet in the stream, 
with not less than half a gallon of water per minute, with 
a supply-pipe forty feet long, will elevate water to a 
height as great as the strength of common half-inch lead 




Water-ram. 



228 MACHINERY IN CONNECTION WITH WATEE. 

pipe will bear.* The greater the height, in proportion to 
the fall of the stream, the less will be the quantity of wa- 
ter elevated, as compared with the quantity flowing in 
the stream, or escaping from the waste valve. 

H. L. Emery gives the following rule for determining 
the quantity of water elevated from a stream : — Divide 
the elevation to be overcome by the fall in the drive-pipe, 
and. the quotient will be the proportion of water, (passing 
through the drive-pipe), which will be raised, — deducting, 
also, for waste of power and friction, say one-fourth the 
amount. Thus, with 10 feet fall, and 100 feet elevation, 
one-tenth of the water would be raised if there were no 
friction or loss ; but, deducting, say one-fourth for these, 
seven and a half gallons in each hundred gallons 
would be raised, the rest escaping, or being required to 
accomplish this result. Or, if the fall of the water in the 
supply-pipe be 3 feet, and the elevation required in the 
discharge-pipe be 15 feet, about one-seventh part of all 
the water will be elevated to this height of 15 feet. But 
if the desired height be 30 feet, then only about one-four- 
teenth part of the water will be raised ; and so on in 
about the same ratio for different heights. A gallon per 
minute from the spring would elevate six barrels five 
times as high as the fall, in twenty-four hours, and at the 
same rate for larger streams. With a head of 8 or 10 
feet, water may be driven up to a height of 100, or even 
150 feet, provided the machine and pipes are strong 
enough. The best result is obtained when the length of 
the drive-pipe and the momentum it produces are just suf- 
ficient to overcome the reaction caused by the closing of 

* When water is raised to a considerable elevation by means of the 
water-ram, the reservoir must possess great strength. If the height be 
100 feet, the pressure, as shown on a former page, is about forty-four 
pounds to the square inch. With an internal surface, therefore, of only 
2 square feet, the force exerted by the column of water, tending to 
burst the reservoir, would be equal to more than twelve thousand 
pounds. 



THE WATER-RAM. 229 

the waste valve at each pulsation, and prevent the current 
of water from being thrown backward or up the drive- 
pipe ; hence, the greater the disproportion between the 
foil and the required elevation, the longer or larger must 
be the drive-pipe, in order to obtain sufficient momentum. 
A descent of only a foot or two is sufficient to raise water 
to moderate elevations, but the drive-pipe should be of 
large bore. This pipe should always be very nearly 
straight, so that the water, by having a free course, may 
acquire sufficient momentum to compress the air in the 
ram, and push the water up the discharge-pipe. Water 
may be carried to a distance of a hundred rods or more, 
but as there is some friction in so long a discharge-pipe, 
a greater force is required than for short distances. The 
discharge-pipe should, therefore, be larger, as the length 
is increased. Half an inch diameter is a common size, 
but long pipes may be five-eighths or three-fourths ; and, 
when practicable, it is more economical to reach an eleva- 
tion with a short and strong pipe, and to use a lighter 
and weaker one for the upper part. A pit, lined with 
brick or smooth stone, for placing the ram, protects it 
from freezing ; and both pipes should be under ground 
for the same reason. The supply or drive-pipe is usually 
40 to 50 feet long ; but where the fall is 8 or 10 feet, it 
should be sixty or seventy feet. 

Unlike a pump, there is no friction or rubbing of parts 
in the water-ram, and, with clean water, it will act for 
years without repairs, continuing through day and night 
its constant and regular pulsations, unaltered and unob- 
served. A small quantity of sand, or of dead grass or 
other fibre, in the water, will be liable to obstruct the 
valves, and render frequent attention necessary. 

WATER-ENGINES, 

including those for extinguishing fires and for irrigating 
gardens, are constructed on a principle quite similar to 



230 MACHINERY IN CONNECTION WITH WATEK. 

Fiff. 25G. 




Fig. 257. 



Garden-engine 
that of the water-ram. In- 
stead, however, of compress- 
ing the air, as in the ram, 
by the successive strokes of 
a column of running water, 
it is accomplished by means 
of a forcing-pump, driving 
the water into the reservoir, 
from which it is again ex- 
pelled with great power, by 
means of the elasticity of 
the compressed air. Fig. 256 
represents a garden-engine, 
movable on wheels, which 
may be used for watering 
gardens, washing windows, 
or as a small fire-engine. Fig. 
257 is another, of smaller 
size, for the same purposes, 

and in a neat and compact cylindrical Garden-engbie. 

form, the working part being within the cylindrical case. 




THE FLASH-WHEEL, FOIi IIAISING WATER. 



2S1 



THE FLASH-WHEEL 

is employed with great advantage where the quantity of 
water is large, and is to be raised to a small height, as in 
draining marshes and swamps. It is like an undershot 
wheel with its motion reversed; in iig. 258 the ar- 
rows show the direction of the current when driven up- 
ward. It must, of course, be made to fit the channel 
closely, without touching and causing friction. In its best 
form, its paddles incline backward, so as to be nearly up- 

Fiff. 258. 




Flash or fen wheel for raising water rapidly short distances. 

right at the time the water is discharged from them into 
the upper channel. It has been much used in Holland, 
where it is driven by wind-mills, for draining the surface- 
water off from embanked meadows. In England, it has 
been driven by steam-engines ; and in one instance, an 
eighty-horse-power engine, with ten bushels of coal, raised 
9,840 tons of water six feet and seven inches high, in an 
hour. This is equal to more than 29,000 lbs. raised one 
foot per minute by each horse-power, showing that very 
little force is lost by friction in the use of the flash-wheel. 




232 MACHINERY IN CONNECTION WITH WATER. 

WAVES. 

NATURE OE WAVES. 

An inverted syphon, or bent tube, like that shown in 
fig. 259, may be used to exhibit the F >s- 259. 

principle on which depends the motion 
of the waves of the sea. The action of 
the waves on shores and banks, and the 
inroads which they make upon farms 
situated on the borders of lakes and 
large rivers, present an interesting sub- 
ject of inquiry. 

If the bent tube (fig. 259) be nearly filled with water, 
and the surface be driven down in one arm by blowing 
suddenly into it, the liquid will rise in the other arm. 
The increased weight or head of this raised column will 
cause it to fall again, its momentum carrying it down below 
a level, and driving the water up the other arm. The 
surfaces will, therefore, continue to vibrate until the force 
is spent. The rising and falling of waves depend on a 
similar action. The wind, by blowing strongly on a por- 
tion of the water of the lake or sea, causes a depression, 
and produces a corresponding rise on the adjacent surface. 
The raised portion then falls by its weight, with the add- 
ed force of the wind upon it, until the vibrations increase 
into large waves. 

THE WATER NOT PROGRESSIVE. 

The waves thus produced have a progressive motion 
(for reasons to be presently shown), as every one has ob- 
served. A curious optical deception attending this ad- 
vancing motion has induced many to believe that the 
water itself is rolling onward ; but this is not the fact. 
The boat which floats upon the waves is not carried for- 
ward with them 5 they pass underneath, now lifting it on 



WATER OF WAVES NOT PROGRESSIVE. 233 

their summits, and now dropping it into the hollows 
between. The same effect may be observed with the wa- 
ter-fowl, which sits upon the surface. It often happens, 
indeed, that the waves on a river roll in an opposite di- 
rection to the current itself. 

If a cloth be laid over a number of parallel rollers, so 
far apart as to allow the cloth to fall between them, and a 
progressive motion be then given to them, the cloth remain- 
ing stationary, a good representation of waves will be 
afforded, and the cloth will appear to advance ; or if a 
strip of cloth be laid on a floor, repeated jerks at one end 
will produce a similar illusion. 

It is only the form of the wave, and not the water 
which composes it, which has the onward motion. Let 
the dark line in fig. 260 represent the surface of the water. 

Fig. 2G0. 
A 




B 

A is the crest of one of the waves, and being higher than 
the surface at i?, it has a tendency to fall, and B to rise. 
But the momentum thus acquired carries these points so 
far that they interchange levels. The same change takes 
place with the other waves, and the dotted line shows the 
newly formed surface as the water thus sinks in one place 
and rises in another. The same process is again repeat- 
ed, and each wave thus advances further on, and its pro- 
gressive motion is continually kept up. 

BREADTH AND VELOCITY OF WAVES. 

Each wave contains at any one moment particles in all 
possible stages of their oscillation ; some rising, and some 
falling ; some at the top, and some at the bottom ; and 
the distance from any row of particles to the next row 
that is in precisely the same stage of oscillation is called 



234 MACHINERY IN CONNECTION WITH WATER. 

breadth of the wave, that is, the distance from crest to 
crest, or from hollow to hollow. 

There is a striking similarity between the rising and 
falling of waves and the vibrations of a pendulum, and it 
is a very interesting and remarkable fact, that a wave al- 
ways travels its own breadth in precisely the same time 
that a pendulum, whose length is equal to that breadth, 
performs one vibration. Thus, a pendulum 39|- inches 
long beats once in each second, and a wave whose breadth 
is 39J inches travels that breadth in one second. The 
length of a pendulum must be increased as the square of 
the time for its vibrations ; that is, to beat but once in 
two seconds, it must be four times as long as for one 
second ; to beat once in three seconds, it must be nine 
times as long, and so on. In the same way, waves which 
travel their breadth in two seconds are four times as wide 
as those traveling their breadth in one second ; and thus 
their breadth, and consequently their speed, increases as 
the square of the time. Large waves, therefore, roll on- 
ward with far greater velocity than small ones. If only 
thirty-nine inches wide, they move about two and a quar- 
ter miles an hour, and pass once each second ; if 

13 feet wide, they move 4% miles an hour, passing once in 2 seconds. 

52 do. do. 9 do. do. 4 do. 

209 do. do. 18 do. do. 8 do. 

830 do. do. 36 do. do. 16 do. 

Although the water itself does not advance where there 
is much depth, yet when it reaches a shore or beach, the 
hard and shallow bottom prevents it from falling or sub- 
siding, and it then rolls onward with a real progressive 
motion from the momentum it has acquired, breaks into 
foam, and lashes the earth and rocks. The sea billows 
are sometimes twenty-five feet in elevation,* and when 
these advance upon a stranded ship on a lee shore, with 

* No authentic measurement gives the perpendicular height of waves 
more than twenty-five feet. 



PREVENTING THE INROAD OF WAVES. 235 

the speed of a locomotive, their effects are in the highest 
degree appalling; and iron bolts are snapped, and massive 
timbers crushed beneath their violence. 

PREVENTING THE INROAD OP WAVES. * 

To prevent the inroads of lake waves upon land, the 
remedies must vary with circumstances. The difficulty 
would be small if the water always stood at the same 
height. The greatest mischief is usually -done when they 
rise over the beach of sand and gravel which they have 
beaten for centuries. Wooden bulwarks soon decay. 
Where loose stones can be had in large quantities, form- 
ing sloping rip-rap walls, they may be cheapest ; but they 
are not unfrequently placed too near low-water mark to 
protect the banks. Substances which offer a gradual im- 
pediment to the waves are often quite effectual, though 
not formidable in themselves. It is curious to observe how 
so slender a plant as the bulrush, growing in water several 
feet deep, will destroy the force of waves. If it grew 
only near the shore, where the water has progressive mo- 
tion, it would soon be dashed in heaps on the beach. 
Parallel hedge-rows of the osier willow, protected by a 
wooden barrier until well grown and established would, 

in many cases, prove efficient. 

Stones and timber bulwarks are often made needlessly 
F .„ 261 liable to injury by 

being built nearly 
perpendicular, and 
the waves break 
suddenly, and w T ith 
full force, like the 
blows of a sledge against them. A better form is shown 
in fig. 261, where a slope is first presented, to weaken their 
force without imposing a full resistance, and their 
strength is gradually spent as they rise in a curve. A 




236 MACHINERY IN CONNECTION WITH WATER. 

more gradual slope than the figure represents would be 
still better. It is on this principle that the stability of the 
world-renowned Eddystone light-house depends. The 
base spreads out in every direction, like the trunk of a 
tree at the roots ; and although the spray is sometimes 
dashed over its lofty summit by the violence of the storm, 
it has stood unshaken on its rocky base far out in the sea, 
against the billows and tempests, for nearly a century. 

An instance occurred many years ago in England, where 
the superiority of knowledge over power and capital 
without it was strongly exemplified. The sea was mak- 
ing enormous breaches on the Norfolk and Suffolk coast, 
and inundated thousands of acres. The government com- 
missioners endeavored to keep, it out by strong walls of 
masonry and breakwaters of timber, built at great ex- 
pense ; but they were swept away by the fury of the bil- 
lows as fast as they were erected. A skillful engineer 
visited the place, and, with much difficulty, persuaded 
them to adopt his simple plan. Observing the slope of 
the beach on a neighboring shore, he directed that suc- 
cessive rows of fagots or brush be deposited for retaining 
the sand, which was carted from the hills, forming an em- 
bankment with a slope similar to that of the natural 
beach. Up this slope the waves rolled, and became grad- 
ually spent as they ascended, till they entirely died away. 
The breach was effectually stopped, and this simple struc- 
ture has ever since resisted the most violent storms of 
the German Ocean. 

CONTENTS OF CISTERNS. 

Connected with the subject of hydraulics is the collec- 
tion and security of water falling upon roofs, in all cases 
where a deficiency is felt by farmers in the drought of 
summer. The amount which falls upon most farm-build- 
ings is sufficient to furnish a plentiful supply to all the 



CONTENTS OP CISTERNS. 237 

domestic animals of the farm when other supplies fail, if 
cisterns large enough to hold it were only provided. 
Generally speaking, none at all are connected with barns 
and out-buildings, and even when they are furnished, 
they are usually so small as to allow four-fifths of the 
water to waste. 

If all the rain that descends in the Northern States of 
the Union should remain upon the surface, without sink- 
ing in or running off, it would form, each year, a depth 
of about three feet. Every inch that falls upon a roof 
yields two barrels for each space ten feet square; and 
seventy-two barrels a year are yielded by three feet of 
rain. A barn thirty by forty feet supplies annually 
from its roof eight hundred and sixty-four barrels, or 
enough for more than two barrels a day for every day in 
the year. Many farmers have in all five times this 
amount of roof, or enough for twelve barrels a day, year- 
ly. If, however, this water were collected, and kept for 
the dry season only, twenty or thirty barrels daily might 
be used. 

In order to prevent a waste of water on the one hand, 
and to avoid the unnecessary expense of too large cisterns, 
their contents should be determined beforehand by calcu- 
lation. 

RULE FOR DETERMINING THE CONTENTS. 

A simple rule to determine the contents of a cistern, 
circular in form, and of equal size at top and bottom, is 
the following :— Find the depth and diameter in inches; 
square the diameter, and multiply the square by the deci- 
mal .0034, which will give the quantity in gallons* for one 
inch in depth. Multiply this by the depth, and divide by 



* This is the standard gallon of 231 cubic inches. The gallon of the 
State of New York contains 221.18-i cubic inches, or 6 pounds at its 
maximum density. 



238 MACHINERY IN CONNECTION WITH WATER. 

31^-, and the result will be the number of barrels the cis- 
tern will hold. 

For each foot in depth, the number of barrels answer- 
ing to the different diameters are, 

For 5 feet diameter 4.66 barrels. 

6 " 6.71 " 

7 " 9.13 u 

8 " 11.93 " 

9 " 15.10 " 

10 " 18.65 " 

By the rule above given, the contents of barn-yard 
cisterns and manure tanks may be easily calculated for any 
size whatever. 

The size of cisterns should vary according to their in- 
tended use. If they are to furnish a daily supply of 
water, they need not be so large as for keeping supplies 
for summer only. The average depth of rain which falls 
in this latitude, although varying considerably with season 
and locality, rarely exceeds seven inches for two months. 
The size of the cistern, therefore, in daily use, need never 
exceed that of a body of water on the whole roof of the 
building, seven inches deep. To ascertain the amount of 
this, multiply the length by the breadth of the building, 
reduce this to inches, divide the product by 231, and the 
quotient will be gallons for each inch of depth. Multiply- 
ing by 7 will give the full amount for two months' rain 
falling upon the roof. Divide by 31^-, and the quotient 
will be barrels. This will be about fourteen barrels for 
every surface of roof ten feet square when measured hori- 
zontally. Therefore, a cistern for a barn 30 by 40 feet 
should hold one hundred and sixty-eight barrels ; that is, 
as large as one ten feet in diameter, and nine feet deep. 
Such a cistern would supply, with only thirty inches of 
rain yearly, no less than six hundred and thirty barrels, 
or nearly two a day. 

Cisterns intended only for drawing from in times of 
drought, to hold all the water that may fall, should have 
about three times the preceding capacity. 



PART III. 



MACHINERY IN CONNECTION WITH AIR. 



CHAPTER I. 



PRESSURE OF AIR. 



Pneumatics treats of the me- 
chanical properties of the air. 

The actual weight of the air 
may be correctly found by weigh- 
ing a strong glass vessel furnished 
with a stop-cock, a (fig. 262), after 
the air has been withdrawn from 
it by means of an air-pump. Let 
it be accurately balanced by 
weights in the opposite scale; 
then turn the stop-cock and admit 
the air, and it will immediately 
descend, as shown in the figure. 
The weight of the admitted air 
may be ascertained by adding 
weights until it is again balanced. 



Fi<r. £02. 




Balance for Weighing Air, 



HEIGHT AND WEIGHT OF THE ATMOSPHERE. 

The atmosphere which covers the earth extends upward 

to a height of about fifty or sixty miles. At the surface 

of the earth the air is about eight hundred times lighter 

than the water, and the higher we ascend, the rarer or 

239 



240 



MACHINERY IN CONNECTION WITH AIR. 



lighter it becomes, from the diminished pressure of the 
weight above. At seven miles high, it is four times light- 
er than at the surface ; at twenty-one miles, it is sixty- 
four times lighter ; and at fifty miles, about twenty thou- 
sand times lighter. At this height it ceases to refract the 
rays of the sun so as to render it visible at the earth's sur- 
face ; but if it decreases at the same rate upward, at a 
hundred miles high it must be nearly a thousand million 
times rarer than at the earth. 

If the atmosphere were uniformly of the same density, 
with its present weight, it would reach only five miles 
high. Although so much lighter than water, yet, from 
its great height, it presses upon the surface of the earth 
as heavily as a depth of thirty-three feet of water. This 
is nearly equal to fifteen pounds on every square inch, or 
more than two thousand pounds to the square foot. This 
enormous weight would instantly crush us, did not air, 
like liquids, press in every direction, so that the upward 
exactly counterbalances the downward pressure, and the 
air within the body counteracts that without. 

The weight of the atmosphere is strikingly shown by 

means of an air- 
pump, which pumps 
the air from a glass 
vessel, placed mouth 
downward upon the 
brass plate of the 
machine (fig. 263). 
When the air is 
pumped out, and the 
upward or counter- 
balancing air remov- 
ed, so heavy is the 
load upon the glass 

Air-pump. vegselj that a gtr0Dg 

man could scarcely remove it from the plate, although it 



Fig. 263. 





"WEIGHT OF THE ATMOSPHERE. 241 

be no larger than a small tumbler. A glass jar with a 
mouth six inches across would need a force equal to nearly 
four hundred pounds to displace it. If Fig. 264. 

there be a glass vessel open at both ends, 
the hand placed on the top may be so 
firmly held by the pressure that it can not 
be removed until the air is again admit- 
ted below (fig. 264). If a thin plate of 
glass be placed on the top of this open T h e mZTfdcned 
vessel, on pumping out the air, the ty4w. 

weight will suddenly crush it with a noise like the report 
of a gun. 

Some interesting instances occur in nature of the use 
of atmospheric pressure. Flies walk on glass by means 
of the pressure against the outside of their feet, the air 
having been forced out beneath. In a similar way, some 
kinds of fishes cling to the sides of rocks under water, so 
as not to be swept off by the current. Dr. Shaw threw a 
fish of this kind into a pail of water, and it fixed itself so 
firmly to the bottom, that, by taking hold of the tail, he 
lifted up the pail, water and all. 

It is the pressure of the atmosphere upon water that 
drives it up the barrel of a pump as soon as the air is 
pumped out from the inside. Hence the reason that 
pumps can never be made to draw water more than thirty- 
three feet below the piston, a height corresponding to the 
weight of the atmosphere. In practice they never draw 
water even to this height, as a perfect vacuum can not be 
made by pumping. 

THE BAROMETER. 

On the same principle the Barometer is made. It con- 
sists of a glass tube, nearly three feet long, open at one 
end, and which is first filled with mercury, a liquid nearly 
fourteen times heavier than water, The open end is then 
11 




242 MACHINERY IN" CONNECTION WITH AIE. 

placed downward in a cup of mercury. The weight of 
the mercury in the tube causes it to descend until the 
pressure of the atmosphere on the mercury in the cup 
preserves an equilibrium, which takes place when the col- 
umn in the tube has fallen to about two feet and a 
half high, the upper part of the tube being left a 
perfect vacuum, as no air can enter (fig. 265). N*ow, 
as the height of the column of mercury depends 
alone upon the weight of the atmosphere, then, 
whenever the air becomes lighter or heavier, as it 
constantly does during the changes of the weather, 
the rising or falling of the column indicates these 
changes ; and, what is very important, it shows 
the approaching changes of the weather several 
hours before they actually take place. Hence 
it becomes a valuable assistant in foretelling 
the weather. When the mercury falls, showing that 
the atmosphere is becoming lighter, it indicates the 
approach of storms or rain ; when it rises, a settled or fair 
sky follows. These are often foreshown before there is 
any change in the appearance of the sky. For this rea- 
son the barometer is sometimes called a weather-glass. It 
is of the greatest value to navigators at sea. Long 
voyages, which formerly required a year, have been made 
in eight months by means of the assistance afforded by 
the barometer, admitting a full spread of canvas by night 
as well as by day, from the certainty of its predictions. 
On land its indications are not so certain, and at some 
places less so than at others. Sometimes, and more com- 
monly during autumn and winter, the sinking of the mer- 
cury is followed only by wind instead of rain. There is, 
however, no doubt that its use would be of much advant- 
age in large farming establishments, more especially dur- 
ing the precarious seasons of haying and harvesting. 

The barometer is an instrument of great value in de- 
termining with little labor, and with considerable accuracy, 



THE BAROMETER. 243 

the heights of mountains, hills, and the leading points of 
an extensive district of country. In rising above the level 
of the sea, the weight of the air above us becomes less ; 
that is, the pressure of the air upon the barometer de- 
creases, and the column of mercury gradually falls as we 
ascend. To determine, therefore, the height of a mount- 
ain, we have only to place one barometer at its foot while 
another stands at the top, and then, by observing the 
difference in the height of the mercury, we are enabled to 
calculate the height of the mountain. The following ta- 
ble shows how much the barometer falls at different alti- 
tudes, thirty inches being taken for the sea-level:* 

At 1,000 feet above the sea, the column falls to 28.91 inches. 

2,000 " " " " " 27.86 " 

3^000 « " " " " 26.85 " 

4,000 " " " " " 25.87 " 

5^000 " " " " " 24.93 " 

lmile " " " " 24.67 " 

2 u u « « « 20.29 " 

3 « " « " " 16.68 " 

4 « « « " " 13.72 " 

5 » " " " " 11.28 " 
10 " " " " " 4-24 " 
15 « " " " " 1.60 " 
20 " " " " " 0.95 " 

At the level of the sea, the barometer falls about one 
hundredth of an inch for a rise of nine feet, or a little 
more than the tenth of an inch for a rise of one hundred 
feet. At a height of one mile it requires about eleven 
feet rise to sink the mercury a hundredth of an inch. 

In selecting land in mountainous districts of the coun- 
try, where degrees of frost increase with increased alti- 
tudes, and where the height of one portion above another 
has an important relation to the cost of drawing loads up 

* The mercury rarely stands as high as 30 inches at the level of the 
sea, the mean height being about 29.5 inches. But this does not affect 
the measurement of heights, which is determined, not by the actual 
height, but by the difference in heights. 



244 



MACHINERY IN CONNECTION WITH AIR. 



and down hill, the barometer might become of much 
practical value. 



THE SYPHON. 




The syphon operates on a principle quite similar to that 
of the pump ; but, instead of pumping out the air of the 
tube through which the water rises, a vacuum is created 
Fig. 266. by the weight of a column of water, in 

the following way : Fig. 26G represents a 
syphon, which is nothing more than a 
tube bent in the form of a letter U in- 
verted. Now, if this be filled through- 
out with water, and then placed with the 
shorter arm in the vessel of water, A, 
the weight of the column of water in the 
longer arm, Avhich is outside, will over- 
balance the weight of the other column, 
and will therefore run out in a stream. This tends to cause 
a vacuum in the tube, which is instantly filled by the water 
rushing up the shorter arm, being driven up by the press- 
ure of the atmosphere. A stream will consequently con- 
tinue running through the syphon until the vessel is 
drained. 

The syphon may sometimes be very usefully employed in 
emptying pools or 
ponds of water on 
high ground, with- 
out the trouble of 
cutting a ditch for 



this purpose. For 
instance, let a (fig. 267) represent a body of water which 
it is desirable to drain off; by placing the lead tube, b c, 
so that the arm, c, may be lowest, and apjuying a pump 
at this arm to withdraw the air and fill the syphon with 
water, it will commence running, and continue until the 




WINDS. 245 

water has all been drawn off. Difficulties, however, some- 
times occur. If the tube is small and very long, and the 
descent is trifling, the friction of the water in the tube 
may prevent success. "Water usually gives out small 
quantities of air, which collects in the higher part of the 
syphon, and after a while fills it, causing the stream to 
cease running ; but syphons for this purpose, when only a 
few rods in length, with several feet descent, are usually 
found to succeed well. If the discharging orifice is sev- 
eral times smaller than the tube, it is frequently of material 
use, by causing a slow and steady current through the 
syphon. 



CHAPTER II. 

MOTION OF AIR. 
WINDS. 

Wind is air in motion. Its force depends on its speed. 
When its motion is slow, it constitutes the soft, gentle 
breeze. As the velocity increases, the force becomes 
greater, and the strong gale sweeps around the arms of 
the wind-mill with the strength of many horses, and huge 
ships are driven swiftly through the waves by its press- 
ure. By a still greater velocity of the air, its power be- 
comes more irresistible, and solid buildings totter, and 
forest trees are torn up by the roots in the track of the 
tornado. 

The force of wind increases directly as the square of 
the velocity. Thus a wind blowing ten miles an hour ex- 
erts a pressure four times as great as at five miles an hour, 
and twenty-five times as great as at two miles an hour. 



246 



MACHINERY IN CONNECTION WITH AIR. 



The following table exhibits the force of wind at different 
degrees of velocity : 

Description. 

Hardly perceptible. 

Just perceptible. 



Miles an 
hour. 

1 

2 

3 

4 

5 

6 

7 
10 
15 
20 
25 
30 
35 
40 
45 
50 
60 
80 
100 



Pressure in lbs. on 
a square foot. 

.005 
.020 
.045 
.080 
.125 
.180 
.320 
.500 



1 
f 

L80 ) 

}2oy 

.500 ) 
1.125 \ 

\ 
\ 

000 ) 
125 f 



2.000 

3.125 

4.500 

6.125 

8.000 

LO 

12.500 

18.000 

32.000 

50.000 



Light breeze. 
Gentle, pleasant wind. 
Pleasant, brisk wind. 
Very brisk. 
Strong, bigb wind. 

Very high. 

Storm or tempest. 
Great storm. 
Hurricane. 

Tornado, teariug up trees, and sweeping off 
buildings. 

These forces may be observed at a time when the air is 
still, by a forward motion equal to that of the wind. Thus 
walking moderately gives the faint breeze against the 
face ; riding in a wagon at six miles an hour causes the 
sensation of a pleasant wind ; the deck of a steam-boat at 
fifteen miles produces a brisk blow ; while an open rail-car 
at forty miles an hour occasions a sweep of the air nearly 
resembling a tempest. 

The preceding table will enable any one to calculate 
with considerable accuracy the amount of draught which 
a horse must constantly overcome in traveling with a 
covered carriage against the wind, adding, of course, the 
speed of the horse to that of the wind. For example, 
suppose a horse with a covered carriage is driven against 
what we term " a very brisk wind," blowing 24 miles an 
hour, and pressing 3 lbs. on the square foot. The carriage 
top offers a resisting surface four feet square, or with six- 



MOTION AGAINST THE WIND. 247 

teen square feet. Three times sixteen, or 48 lbs., are con- 
sequently required to be overcome with every onward 
step of the horse. Now, we have already seen, when 
treating of " application of labor," that a horse traveling 
three miles an hour for eight hours will overcome only 83 
lbs. with ordinary working, which is not double the resist- 
ance of the wind. Hence we perceive that more than 
half the horse's strength is lost by driving against such a 
current. At six miles an hour, all his strength, without 
over-driving, would be expended in overcoming the force 
of the wind, and the power required for moving the car- 
riage would be so much excess of labor. For simplifying 
the operation, the increased motion of the wind occasion- 
ed by driving against it has not been taken into account. 
Even with a small pressure, the loss in power is consid- 
erable for an entire day. When, for example, the air is 
perfectly still, traveling six miles an hour will cause a con- 
stant resistance of 3 lbs. on the carriage, or one-fourteenth 
of the power exerted for a full day's work. The same 
speed against a " gentle wind " of six miles an hour, add- 
ed, would increase the resistance fourfold, or equal to 12 
lbs. ; more than one-fourth of the horse's strength at six 
miles an hour through the day. 

WIND-MILLS. 

The power possessed by the sails of a wind-mill may be 
nearly ascertained in the same way, the area of the sails 
being known, and first deducting their average velocity. 

In all wind-mills, it is important that the sails should 
have the right degree of inclination to the direction of the 
wind. If they were to remain motionless, the angle 
would be different from that in practice. They should 
more nearly face the wind ; and as the ends of the sails 
sweep around through a greater distance and faster, they 
should present a flatter surface than the parts nearer the 



248 



MACHINERY IX CONNECTION WITH AIR. 



centre. The sails should, therefore, have a twist, to give 
them the most perfect form, so that the parts nearest the 
centre may form an angle of about 68 degrees with the 
wind, the middle about 72 degrees, and the tips about 83 
degrees. 

In order to produce the greatest effect, it is necessary to 
give the sails a proper velocity as compared with the ve- 
locity of the wind. If they were entirely unloaded, the ex- 
tremities would move faster than the wind, in consequence 
of its action on the other parts. The most useful effect is 
]3roduced when the ends move about as fast as the wind, 
or about two-thirds the velocity of the average surface. 

The most useful wind is one that moves at the rate of 
eight to twenty miles per hour, or with an average press- 
ure of about one pound on a square foot. In large wind- 
mills, the sails must be lessened when the wind is stronger 

than this, to prevent the 
arms from being broken ; 
and if much stronger, it 
is unsafe to spread any, 
or to run them. 

The force of wind may 
be usefully applied by al- 
most every farmer, as it 
is a universal agent, pos- 
sessing in this respect 
great advantages over 
water-power, of which 
very few farms enjoy 
the privilege. 

Wind may be applied 
to various purposes, such 
as sawing wood by the 
aid of a circular saw, 
turning grindstones, and particularly in pumping water. 
One of the simplest contrivances for pumping is represented 




Wind-mill for pumping water on farms , 
A, wind-mill; B,vane; 1, pump-rod. 



WIND-MILL FOR TUMPING WATER. 



249 



by fig. 268, where A is the circular wind-mill, with a number 
of sails set obliquely to the direction of the wind, and al- 
ways kept facing it by means of the vane, B. The crank of 
the wind-mill, during its revolutions, works the pump-rod, I, 
and raises the water from the well beneath. In whatever di- 

Flg; 2G0. 




Barn surmounted with wind-mill for pumping water t 
cutting straw, t{C. 

rection the wind may blow, the pump will continue work- 
ing. The pump-rod, to work steadily, must be immediately 
under the iron rod on which the vane turns. If the di- 
ameter of the wind-mill is four feet, it will set the pump 
in motion even with a light breeze, and with a brisk wind 
will perform the labor of a man. Such a machine will 
pump the water needed by a herd of cattle, and it may be 
placed on the top of a barn, with a covering, to Avhich may 
be given the architectural effect of a tower or cupola, as 
shown in fig. 269. 

A more compact machine, but of more complex con- 
struction, is shown in fig. 270, where the upper circle 
moves around with the wheel and vane on the fixed lower 
circle, to which it is strongly secured so as to admit of 
turning freely. In other respects it is similar to the pre- 
ceding. 

11* 



250 MACHINERY IN CONNECTION WITH AIR. 

Fte. 270. 




Wind-mills, like the preceding, which have fixed sails, 
should not be more than three or four feet in diameter ', 
and even then will require care in storms. If larger, 
they will become broken by severe winds. The remedy is 
either to move the sails by hand at every considerable 
change in the. force of the current, which would require 
nearly constant attention ; or to use the self-regulating ma- 
chines, of which there have been several invented, some 
of which have proved useful and durable. 

Halliday's wind-mill has been much used for several 
years, and is made of various sizes, the larger possessing 
the power of several horses. It is self-regulated, in the 
following manner : When the mill begins to run too fast, 
it pumps water rapidly into a chamber or cylinder, and 
this increase of water moves an arm which turns the fans 



•BROWN S WIND-MILL. 



251 



edgewise to the wind. When the wind slackens, a re- 
verse movement takes place. 

Brown's wind-mill, made by the Empire Wind-mill Com- 
pany, of Syracuse, is a more recent invention, and has 
proved very successful. The annexed figure (fig. 271), rep- 
rig. 271. 




Brown's {or Empire) Wind-mill. 

resents one of the smaller sizes, adapted to farm jmrposes 
and pumping water for cattle. It is regulated in part by 
the centrifugal force of weights, and partly by the direct 
pressure of the wind. This regulating contrivance ren- 
ders the mill safe, even in a gale of wind. The larger 



252 MACHINERY IN CONNECTION WITH AIR. 

sizes, which are fifty feet or more in diameter, possess 
much power, and are used for grinding grain, and other 
purposes. 

The work which a wind-mill is capable of doing de- 
pends very much on the site. If placed where the wind 
has a long, uniform, and steady sweep, it will accomplish 
much more, and to better satisfaction, than if among hills 
or other obstructions, where the blasts are uncertain and 
changing. 

Wind-mills of large size are peculiarly adapted to pump- 
ing water into reservoirs, or from mines or quarries, w T here 
a few days of calm weather will not result in inconven- 
ience ; but they are not suited to manufactories where a 
constant power is required to furnish employment to men, 
but can be used for work w r hich may be intermitted or 
changed. 

Brown's wind-mill is sold at $75 dollars for the small 
size, with increase of prices up to $1,200 for large ones. 

CAUSES OF WIND. 

The motion of air, in producing wind, is explained by 
the action of heat, although there are many irregular cur- 
rents whose cause is not well understood. The simplest 
illustration of the effect of heat in causing currents is fur- 
nished by the land and sea-breezes in warm latitudes. 
The rays of the sun during the day heat the surface of 
the land, and the air in contact with it, also becoming 
heated, and thus rendered lighter, flows upward ; the air 
from the sea rushes in to fill the vacancy, and causes the 
sea-breeze. During the night, the radiation of heat from 
the land into the clear sky above cools the surface to a 
lower temperature than that of the sea ; consequently, 
the air in contact with the sea becomes heated the most, 
and rising, causes the wind from the land to flow in and 
supply the place. Trade-winds are caused in a similar 



CHIMNEY CURRENTS. 253 

way, but on a much larger scale, by the greater heat of 
the earth at the equator, which produces currents from 
colder latitudes. These currents assume a westerly tend- 
ency, in consequence of the velocity of the earth being 
the greatest at the equator, and which, outstripping the 
momentum which the winds have acquired in other lati- 
tudes, tends to throw them behind, or in a westerly di- 
rection. 

CHIMNEY CURRENTS. 

Chimney Currents are produced by the heat of the fire 
rarefying the air, which rises, and carries the smoke with 
it. The taller the chimney is, the longer will be the 
column of rarefied air tending upward ; and, as a conse- 
quence, the stronger will be the draught. In kindling a 
fire in a cold chimney, there is very little current till this 
column becomes heated. The upward motion of heated 
currents is governed by laws similar to the downward mo- 
tion of water in tubes, where the velocity is increased 
with the height of the head. But as air is more than 
eight hundred times lighter than water, slight causes will 
affect its currents, which would have no sensible influence 
on the motion of liquids. For instance, a strong wind 
striking the top of a chimney may send the smoke down- 
ward into the room ; and a current can not be induced 
through a horizontal pipe without connecting with it an 
upright pipe of considerable height. 

CONSTRUCTION OF CHIMNEYS. 

In constructing chimneys to produce a strong draught, 
the throat immediately above the fire, which should have 
a breadth equal to that of the fireplace, should be con- 
tracted to a width of about four inches, so that the column 



254 



MACHINERY IN CONNECTION WITH AIR. 



''V, 



of rising air above may draw the air up through the 
Fig. 2T2. throat with increased velocity, as 

shown in fig. 272. This arrange- Fi m 
raent also allows the fire to be built 
so as to throw the heat more fully 
out into the room. By leaving the 
shoulder at b square or flat, it will 
tend to arrest any reversed or 
downward current in a better man- 
ner than if built sloping, as shown 
by the dotted line at a, which 
would act like a funnel, and throw 
the smoke into the room. The 
throat should be about as high as 
the extreme tip of the flame ; if 
much higher, the chimney will not 
draw so well, and if lower, too 
much of the heat will be lost. 
Fig. 273 shows a fireplace without a contracted throat, 
the current of which is comparatively feeble. Many 
chimneys draw badly by being made too large for the fire 
to heat sufficiently the column of air they contain. 





A well-built 
Chimney. 



A badly-built 
Chimney. 



CHIMNEY-CAPS. 



When wind sweeps over the roof of a high part of the 
building, or over a hill, it often strikes the Fig. 274. 
tops of chimneys below, and drives the smoke 
downward. This may be often prevented 
by placing a cap over the chimney, like that 
represented by fig. 274, which is supported at 
its corners, the smoke passing out at the four 
sides just under the eaves of this cap. But 
it sometimes happens that there is a confusion of currents 
and eddies at the top of the chimney, over which this cap 




CHIMNEY-CAPS. 



255 



Fisr. 275. 





has no influence. In this case, the cap represented by fig. 
275 furnishes a complete remedy, and is, in- 
deed, perfect in its operation under any cir- 
cumstances whatever, for the chimney sur- 
mounted by it will always draw when there 
is wind from any quarter, with or without a 
fire. It has effected a perfect cure in some 
chimneys which before were exceedingly 
troublesome, and were regarded as incurable. Fig. 276 is 
intended to show the mode of its Fig. 276. 

operation ; the wind, as shown by 
the arrows, being deflected for a 
considerable distance on the lee 
side, so as to form a vacancy at a, 
which the wind from the other end 
and from the chimney both rush in to supply. Being 
fixed on without turning in the chimney, it is both simpler 
and less noisy than any caps furnished with a vane. 

Emersorfs Chimney-cap is different in construction, 
Fig. 277. but quite simi- Fig. 278. 

lar in principle 
to the preced- 
ing. It is shown 
bf fig. 277. A 
sheet-iron pipe 
is set in the top 
of the chimney, 
furnished with 
the conical rim, and a plate 
or fender on the top, which ex- 
cludes the rain. Between the 
plate and rim is a space quite 
similar in form or section to 
that represented by fig. 276. 
In exposed situations, chim- 
neys are found to draw more uniformly by contracting 





256 



MACHINERY IN CONNECTION WITH ATE. 



the top about a third less than the rest of the flue. The 
Fig. 279. current at the moment of escape is swifter 
than below, and less acted upon by any down- 
ward blast of the wind, at the same time 
that the surface is smaller on which the wind 
can strike the current, as shown in fig. 278. 
A chimney of this character may be very 
easily made by contracting the tiers of brick, 
thus giving to it an ornamental appearance, 
as seen in fig. 279.* 




* Where different fires communicate with the same chimney, separate 
flues should be built for each fire, ana kept separate in the same chim- 
ney-stack, carried up independently of each other. But even with this 
precaution, smoky rooms will not be avoided, unless the termination of 
the chimney is of the right form, of which the following illustration is 
given in Allen's Rural Architecture : 

"Fifteen years ago we purchased and removed into a most substantial 
and well-built stone house, the chimneys of which were constructed 
with open fireplaces, and the flues carried up separately to the top, 
where they all met upon the some level surface, as chimneys in past times 
usually were built thus (fig. 2S0). Every fireplace in the house (and some 
of them had stoves in) smoked intolerably; so much so, that when the 
wind was in some quarters, the fires had to be put out in every room 
but the kitchen, which, as good luck would have it, 6moked less — al- 
though it did smoke there — than the others. After balancing the mat- 
ter in our own mind some time whether we would pull down and re- 
build the chimneys altogether, or attempt an alteration — as we had 

Fig. 281. 



Tis. 2so. 



given but little thought to the sub- 
ject of chimney draught, and to try 
an experiment was the cheapest — 
we set to work a bricklayer, who, 
under our direction, simply built 
over each discharge of the several 
flues a separate top of fifteen inches 
high, in this wise : Fig. 281. The / 
remedy was perfect. We have had no smoke in the house since, blow 
the wind as it may, on any and on all occasions. The chimneys can't 
smoke ; and the whole expense for four chimneys, with their twelve 
flues, was not twenty dollars ! The remedy was in giving each outlet a 
distinct current of air all around, and ou every side of it." 




VENTILATION OF ROOMS. 



257 



Fie:. 282. 



VENTILATION. 

Impure air may be breathed for a short time without 
any serious detriment, but to live in it and respire it for 
years can not fail to produce permanent injury to the 
health. During the heat of summer, open doors and win- 
dows will usually furnish plenty of fresh air, so long as 
this season lasts, which in the Northern States is not one 
half the year. During the rest of the time, rooms are 
heated with close stoves, and unless special care is taken 
to secure fresh air, pale or sickly inmates wilt be the most 

likely results. 

Even with a common open fireplace, which causes more 
circulation of the air in a room than stoves, the ventila- 
tion is very imperfect. The following figure (fig. 282) 

represents the fresh air 
as passing in from an 
open window opposite 
the fire, producing a 
direct current from the 
window to the chim- 
ney, and leaving all the 
upper portion of the 
room filled with bad 
air, unaffected by the 
chancre. The cold air 
can not rise, nor the 
a badhj-vudiiaud Room. -j^t air descend. This 

difficulty may be easily removed by placing a register 
(which may be closed or opened at pleasure) at a, in the 
upper corner, so that the confined air may escape into the 
chimney. Without this provision, it is nearly impossible 
to preserve the air in proper condition for breathing, for 
the upper part, being warmest and lightest, remains un- 
changed at the top. In rooms heated by stoves, registers 
for the escape of the foul air are still more important, where 




258 



MACHINERY IX CONNECTION "WITH AIK. 



the thermometer frequently indicates twenty degrees dif- 
ference in the heat above and at the floor, the lower 
stratum of air resting like a cold lake about the feet, 
while the head is heated unduly. 

When the draught of the chimney-fire is not strong, 
the smoke may, however, escape through the ventilating 
register into the room. To avoid this difficulty, it is best 
to provide separate air-flues in the walls when the house 
is built, for effecting perfect ventilation. In rooms strong- 
ly heated by fires, the fresh air should be admitted near 

the ceiling, producing descending 

currents, and effecting a complete 

circulation in the air of the room. 

But in sleeping apartments, and in 

closets, not heated artificially, and 

where the descending currents will 

not take place, the fresh air should 

Mode of ventilating Garrets. \)Q admitted through a register or 

small rolling blind near the floor, and discharged near the 

ceiling into an air-flue. 

The excessive warmth of garrets in midsummer may 



Fisr. 283. 




Fig. 2S5. 



Fig. 284. 




Mode of Ventilating half-story Bod- 
rooms. 




Griffith's Ventilator. 

be avoided by placing a ventilator at the highest part, 



Griffith's patent ventilator. 259 

and admitting air at windows or openings near the eaves 
(fig. 283), thus sweeping all the hot air out by the cur- 
rent produced ; or the oppressive heat of half-story bed- 
rooms may be similarly avoided, by creating a current of 
air between the roof and the plastering (fig. 284). Two 
modes may be adopted, as represented on each side of the 
figure. 

Fig. 285 represents Griffith's patent ventilator, for chim- 
neys, and for giving a current of air through apartments. 
It is made of iron, working as a screw fan, the slightest 
wind causing it to revolve and establish a current through 
the pipe which it surmounts. 



PART IV. 

HEAT. 



CHAPTER I. 

CONDUCTING POWER OF BODIES. 

When any substance or body has become heated, it 
loses its heat in two different ways, by conduction and by 
radiation. When conducted, heat passes off slowly or 
gradually through bodies, as when a pin is held by the 
hand in a candle, the heat advances from, one end to the 
other till it burns the fingers ; or, when an iron poker is 
thrust into the fire, the heat gradually passes through it 
till the whole becomes hot. Iron and brass are, there- 
fore, said to be good conductors of heat. The end of a 
pipe-stem may, however, be heated to redness, and a 
wooden rod may be set on fire without even warming the 
other extremity, because the heat is very slowly conducted 
through them. Wood and burned clay are, therefore, 
poor conductors. 

The comparative conducting power of different sub- 
stances may be shown by placing short rods of each with 
one of their ends in a vessel of hot sand, the others to be 
tipped with wax. The different periods of time required 
to melt the wax indicate the relative conducting powers. 
It will speedily melt on the copper rod ; soon after, on 
the rod of iron ; glass will require longer time ; stone or 
earthenware, still longer; while on a rod of wood, it 
will scarcely melt at all. These rods should be laid hori- 
zontally, that the hot air rising from the sand may not 
260 



UTILITY OF THE CONDUCTING POWER OP BODIES. 261 

affect the wax. The conducting powers may be judged 
of, likewise, with considerable accuracy in cold w r eather, 
by merely placing the hand upon the different substances. 
The best conductors will feel coldest, because they with- 
draw the heat most rapidly from the hand. Iron will feel 
colder than stone ; stone colder than brick ; wood, still 
less so ; and feathers and down, least of all, although the 
real temperature of all may be precisely the same. 

UTILITY OF THIS PRINCIPLE. 

A knowledge of this property is often very useful. For 
instance, it is found that hard and compact kinds of wood, 
as beach, maple, and ebony, conduct heat nearly twice as 
rapidly as light and porous sorts, like pine and bass-wood. 
Hence, doors and partitions made of light wood make a 
warmer house than those that are more heavy and com- 
pact. Pine or bass-wood would, in this respect, be better 
than oak or ash. 

Porous substances of all kinds are the poorest conduct- 
ors ; sawdust, for example, being much less so than the 
wood that produced it. For this reason, sawdust has 
been used as a coating around the boilers of locomotives, 
to keep in the heat, and for the walls of ice-houses, to ex- 
clude it. Sand, filled in between the double walls of a 
dwelling, renders it much warmer in winter, and cooler 
in summer, than if sandstone were made to fill the same 
space. Ashes, being more porous, are found to be still 
better. Tan, which is similar to sawdust, is well adapted 
to filling in the walls of stables and poultry -houses, where 
more than usual warmth in winter is required. Confined 
air is a very poor conductor of heat ; hence the advantage 
of double walls and double windows, provided there are 
no crevices for the escape of the confined air. This prin- 
ciple has been lately applied in the manufacture of hollow 
brick for building the walls of dwellings. 



2G2 



HEAT. 



The light and porous nature of snow renders it eminent- 
ly serviceable as a clothing to the earth in the depth of 
winter, preventing the escape of the heat from below, and 
protecting the roots of plants from injury or destruction. 
Hence the very severity of the cold of the Northern re- 
gions, by producing an abundance of those beautiful 
feathery crystals which form snow, becomes the means of 
protecting from its own effects the tender herbage buried 
beneath this ample shelter. 

CONDUCTING POWER OF LIQUIDS. 



Fi?. 28fi 



Liquids are found to conduct heat very slowly, and 
they were for a long time considered perfect non-conduct- 
ors. Some interesting experiments have been performed 
in illustration of this property. A large glass jar may be 
filled with water (fig. 286), in which may be fixed an 
air thermometer, which is always quickly sensitive to 
small quantities of heat. A shallow cup of ether, floating 

just above the bulb, may be set on 
fire, and will continue to burn for 
some time before any effect can be 
seen upon the thermometer. The 
upper surface of a vessel of water 
has been made to boil a Ions: time 
with a piece of unmelted ice at the 
bottom. Liquids are found, how- 
ever, to possess a conducting power 
in a very slight degree. 

When a vessel of water is heated 
in the ordinary way over a fire, 
the heat is carried through it merely by the motion 
of its particles. The lower portion becomes warm, 
and expands; it immediately rises to the surface, and 
colder portions sink down and take its place, to ascend in 
their turn. In this way, a constant circulation is kept up 




EXPANSION BY HEAT. 



26; 



among the particles. These rising and descending cur- 
rents °are shown by the arrows in fig. 287. This result 
may be easily shown by filling a flask with water into 
which a quantity of sawdust from some green hard wood 
has been thrown, which is about as heavy as water. It 
will traverse the vessel in a manner precisely as shown 
in the figure. 

These results indicate the importance of applying heat 
directly to the bottom of all vessels in which water is in- 
tended to be heated. A considerable loss of heat often 
occurs when the flame is made to strike against the sides 
only of badly arranged boilers. 

EXPANSION BY HEAT. 

An important effect of heat is the expansion of bodies. 
Among many ways to show it, an iron rod may be so fit- 
ted that it will just enter a hole made for the purpose in 
a piece of sheet-iron. If the rod be now heated in the 
fire, it expands and becomes larger, and can not be thrust 

Fipr. 288. 





into the hole. The expansion may be more visibly shown 
and accurately measured by means of an instrument called 
the Pyrometer (fig. 288). The rod a b, secured to its 



264 HEAT. 

])lace by a screw at «, presses against the lever c, and this 
against the lever or index d, both of which multiply the 
motion, and render the expansion very obvious to the eye 
when the rod is heated by the lamps. If the rod should 
expand one-fiftieth of an inch, and each lever multiplies 
twenty times, then the index (or second lever) will move 
along the scale eight inches ; for 20 times 20 are 400, and 
400-50ths of an inch are 8 inches. 

Many cases showing the expansion of heated bodies oc- 
cur in ordinary practice. One is afforded by the manner 
in which the parts of carriage wheels are bound together. 
The tire is made a little smaller than the wooden part of 
the wheel; it is then heated till, by exjmnding, it be- 
comes large enough to be put on, when it is suddenly 
cooled with water, and, by its powerful contraction, binds 
every part of the wheel together with great force. Hogs- 
heads are firmly hooped with iron bands in the same way, 
with more force than could ever be given by driving 
with blows of the mallet. 

This principle was very ingeniously applied in drawing 
together two expanding brick walls of a large building in 
Paris, which threatened to burst and fall. Holes were 
drilled in the opposite walls, through which strong iron 
bars across the building projected, and circular plates of 
iron were screwed on these projecting ends. The bars 
were then heated, which increased their length ; the plates 
were next screwed closely against the walls. On cooling, 
they contracted, and drew the walls nearer together. The 
process was repeated on alternating bars, until the walls 
were restored to their perpendicular positions. 

All tools, where the wooden handles enter iron sockets, 
will hold more firmly if the metal is heated before insert- 
ing the wood. 

The metallic parts of pumps sometimes become very 
difficult to unscrew, and a case has occurred where two 
strong men could not start the screws, until a bystander 



EFFECTS OF SUDDEN EXPANSION. 



265 



suggested that the outer piece "be heated, keeping the in- 
ner cool, when a force of less than ten pounds quickly 
separated them. In other cases, where the large iron nuts 
have been thoughtlessly screwed, while warmed with the 
hands, on the cold metallic axles of wood-sawing ma- 
chines in winter, they have contracted so that the force 
of two or three men has been insufficient to turn them. 

The sudden expansion of bodies by heat sometimes 
causes accidents. Thick glass vessels, when unequally 
heated, expand unequally, and break. Heated plates of 
cast-iron or cast kettles are liable to be fractured by 
suddenly pouring cold water upon them. The same ef- 
fect has been usefully applied in splitting the scattered 
rocks which encumber a farm, and which are too large to 
remove while entire. Fires are built upon them ; the up- 
per surface expands while the lower remains cold, and 
large portions are successively separated in scales, and 
sometimes the whole rock is severed. The only care 
needed is to observe attentively and remove with an iron 
bar any parts which may have become loosened by the 
heat, and which would prevent the heat from passing to 
other portions. One man will thus attend to a large 
number of fires, and will split in pieces ten times as many 
rocks in a day as by drilling and blasting. 



Fijr. 389. 



THE STEAM-ENGINE. 

The Steam-engine owes its power to 
the enormous expansion of water at the 
moment it is converted into steam, which 
is about 1,600 times its bulk when in 
a liquid state. The principle on which 
the steam-engine acts may be understood 
by a simple instrument, represented 
in fi>. 289. A fflass tube with a small 
bulb is furnished with a solid, air- 
tight piston, capable of working up and 
12 




266 HEAT. 

down. The water in the bulb, «, is heated with a 
spirit-lamp or sand-bath ; the rising steam forces up the 
piston. Now, immerse the bulb in cold water or snow, 
and the steam is condensed again into water, the tube is 
left vacant, and the pressure of the atmosphere forces 
down the piston. By thus alternately applying heat and 
cold, it is driven up and down like the piston of a steam- 
engine. The only difference is, the steam-engine is fur- 
nished with apparatus so that this application of heat and 
cold is performed by the machine itself. The bulb repre- 
sents the boiler, and the tube the cylinder ; but in the 
steam-engine, the boiler is separate, and connected by a 
pipe with the cylinder ; and instead of applying the cold 
water directly to the cylinder, it is thrown into another 
vessel, called the condenser, connected with the cylinder. 

When IsTewcomen, who made the first rude regularly 
working engine, began to use it for pumping water, he 
employed a boy to turn a stop-cock connected with the 
condenser, every time the piston made a stroke. The 
boy, however, soon grew tired of this incessant labor, and 
endeavored to find some contrivance for relief. This he 
effected by attaching a rod from the piston or working- 
beam to the cock, which was turned by the machine itself 
at every stroke. This was the origin of the first self- 
acting engine. 

The different parts ot a common steam-engine may be 
understood from the following figures, one representing 
the boiler, and the other the working machinery. 

The boiler, JB (fig. 290), contains water in the lower 
part, and steam in the upper ; F JB is the fire ; v o is the 
feed-pipe y v, a valve, closed by the lever b c a, whenever 
the boiler is full enough, by means of the rising of the 
float, S, and opened whenever the float sinks from low 
water. _3f, barometer gauge, to show the pressure of the 
steam ; w, weight on the lever, e b, for holding down the 
safety-valve : this lever being graduated like a steelyard, 



THE STEAM ENGINE. 



267 



the force of the steam may be accurately weighed. £7" is 
a valve opening downward, to prevent the boiler being 
crushed by atmospheric pressure, by allowing the air to 
pass in whenever the steam happens to decline. Two 



Fig. 290. 




Boiler of Steam-engine. 

tubes, with stop-cocks, c and. d, one just below the water- 
level, and the other just above it, serve to show, by open- 
ing the cocks, whether the water is too high or too low. 

The working part of the engine is represented in the 
figure on the following page (fig. 291). The steam enters 
by the pipe, s, from the boiler on the other side of the 
brick wall, as shown in fig. 290. The steam passes through 
what is called a four-way-cock, a, first into the lower, then 
into the upper end of the cylinder, C, as the piston, P, 
moves up and down ; this is regulated by the levers, y y. 
The piston-rod, E, is attached to the working-beam, JB 
F, turning on the centre, A. The rod, F 7?, turns the fly- 
wheel, H H, and drives the mill, steam-boat, or machinery 
to be set in motion. 



268 



HEAT. 



The condenser,^', shown directly under the cylinder, re- 
mains to be described. It is immersed in a cistern of cold 
water, and is connected by pipes with the upper and lower 
end of the cylinder. Through these pipes the steam 



Through 

Fi.2\ 291. 




Low-pressure Steam-engine, 

passes out of the cylinder, first from one end and then 
from the other, and is condensed into water by a jet of 
cold water thrown into it by the injection-cock. When 
condensed, it is pumped out by the pump, 0, into the well 
or reservoir, W, and then again into the feed-pipe of the 
boiler. Warm water is thus constantly supplied to the 
boiler, and effects a great saving of fuel. 

The supply of steam and the motion of the engine are 
regulated by the governor, G. When the motion is too 
fast, the two suspended balls, which revolve on a vertical 
or upright axis, and which hang loosely like pendulums, 
are thrown out from the axis, producing the movement of 
a rod which shuts the steam-valve. When the motion 



QUALITIES OF THE STEAM-ENGINE. 269 

is too slow, the balls approach the axis, and open the 
valve. 

In high-pressure engines, the steam is not condensed, 
but escapes into the open air at every stroke of the piston, 
which produces the loud, successive puffs of all engines 
of this kind. 

The steam-engine, in its most perfect form, is a striking 
example of human ingenuity, and its qualities are thus 
described by Dr. Arnott : "It regulates with perfect ac- 
curacy and uniformity the number of its strokes in a given 
time, arid records them as a clock does the beats of its 
pendulum. It regulates the quantity of steam ; the brisk- 
ness of the fire ; the supply of water to the boiler ; the 
supply of coals to the fire. It opens and shuts its valves 
with absolute precision as to time and manner ; it oils its 
joints; it takes out any air accidentally entering parts 
which should be vacuous; and when any thing goes 
wrong which it can not of itself rectify, it warns its at- 
tendants by ringing a bell ; yet, with all these qualities, 
and even when exerting a force of six hundred horses, it 
is obedient to the hand of a child. Its aliment is coal, 
wood, and other combustibles. It consumes none while 
idle. It never tires, and wants no sleep. It is not sub- 
ject to any malady when originally well made, and only 
refuses to work when worn out with age. It is equally 
active in all climates, and will do work of any kind ; it is 
a water-pumper, a miner, a sailor, a cotton-spinner, a 
weaver, a blacksmith, a miller, a printer, and is indeed of 
all occupations ; and a small engine in the character of a 
steam pony may be seen dragging after it, on an iron rail- 
way, a hundred tons of merchandise, or a thousand per- 
sons with the speed of the wind." 

Steam-engines have been much used on large farms in 
England for thrashing, grinding the feed of animals, cut- 
ting fodder, and for other purposes. A successful English 
farmer has used a six-horse steam-engine to drive a pair 



270 



HEAT. 



of mill-stones, for thrashing and cleaning grain, elevating 

and bagging it, pumping water for cattle, cutting straw, 

Fig. 292. turning a grindstone, 

and driving liquid ma- 
nure through pipes 
for irrigating his fields, 
employing the waste 
steam in cooking 
food for cattle and 
swine. In this country, 
where horse labor is 
cheaper, steam-engines 
have not come into so 
general use; but on 
large farms, where a 
Wood's Farm Engine. ten - horse - power or 

more is required, they have been employed to much 
advantage, consuming no food, and requiring no care 

Fie. 203. 





Wood's Engine on WJieels, with Pipe Folded Down. 
when idle. Excellent steam-engines for this purpose 
are manufactured by A. N. Wood & Co., of Eaton, 



wood's steam-engine. 271 

Madison Co., N. Y., a representation of which is given 
in the accompanying figure (fig. 292.) When intended to 
move from place to place, these engines are furnished ready 
mounted on wheels (fig. 293). The twelve-horse-power 
engines cost about $1,000, and have thrashed over a hund- 
red bushels per hour, using half a cord of wood, or 300 
or 400 lbs. of coal for ten hours. A Western farmer 
thrashed 14,250 bushels of wheat in five consecutive weeks, 
working five and a half days each, with one of these en- 
gines. The smoke-pipe is guarded, so that straw placed 
within a few inches cannot be set on fire. 

More difficulty obviously exists in adajDting the steam- 
engine to plowing than for stationary purposes. In order 
to possess sufficient power, when used as a locomotive, 
the engine must be made so heavy as to sink in common 
soft soil even with large and broad wheels ; and this 
tendency is increased by the jar of the machinery which 
these wheels support. For this reason, all locomotive 
plows have failed. Better success has attended the use 
of stationary engines, employed for drawing gangs of 
plows, by means of wire rope, across the fields. In Eng- 
land, wiiere much of the soil is tenacious, and where fuel 
and manual labor are cheap, and horse labor expensive, 
this mode of plowing has been found profitable when em- 
ployed on an extensive scale, and is now much used. 

EXCEPTION TO EXPANSION BY HEAT. 

A striking exception to the general law of expansion by 
heat occurs in the freezing of water.* During its change 
to a solid state, it increases in bulk about one-twelfth, and 
this expansion is accompanied with great force. The 
bottoms of barrels are burst out, and cast-iron kettles are 
split asunder, when water is suffered wholly to freeze in 

* There are a very few other substances which expand on passing 
from a liquid to a solid state. 



272 HEAT. 

them. Lead pipes filled with ice expand ; but if it is 
often repeated, they are cracked into fissures. A strong 
brass globe, the cavity of which was only one inch in di- 
ameter, was used by the Florentine academicians for the 
purpose of trying the expansive force of freezing water, 
by which it was burst, although the force required was 
calculated to be equal to fourteen tons. Experiments 
were tried at Quebec, in one of which an iron plug, nearly 
three pounds in weight, was thrown from a bomb-shell to 
the distance of 415 feet ; and in another, the shell was 
burst by the freezing of the water which it contained. 

This expansion has a most important influence in the 
pulverization of soils. The water which exists through 
all their minute portions, by conversion to frost, crowds 
the particles asunder, and when thawing takes place, the 
whole mass is more completely mellowed than could pos- 
sibly be effected by the most perfect instrument. This 
mellowing is, however, of only short duration, if the ground 
has not been well drained to prevent its becoming again 
packed hard by soaking with water. 

But this is not the most important result from the ex- 
pansion of water. Much of the existing order of nature 
and of civilized life depends upon this property ; without 
it the great mass of our lakes and rivers would become 
converted into solid ice ; for, as soon as the surface became 
covered, it would sink to the bottom, beyond the reach of 
the summer's sun, and successive portions being thus add- 
ed, the great body of all large rivers and lakes would 
become permanently frozen. But instead of this disas- 
trous consequence, the ice, by resting upon the surface, 
forms an effectual screen from the cold winds to the wa- 
ter below. 

LATENT HEAT. 

If a vessel of snow, which has been cooled down to 
several degrees below freezing by exposure to the severe 



LATENT HEAT. 273 

cold of winter, be placed over a steady fire with a ther- 
mometer in the snow, the mercury will rise by the increas- 
ing heat of the snow until it reaches the freezing point. 
At this moment it will stop rising, and the snow will be- 
gin to melt ; and although the heat is all the time passing 
rapidly into the snow, the thermometer will remain per- 
fectly stationary until it is all converted to water. The 
heat that goes to melt the snow does not make it any hot- 
ter ; in other words, it becomes latent (the Latin word for 
hidden), so as neither to affect the sensation of the hand 
nor to raise the thermometer. Now it has been found that 
the time required to melt the snow is sufficient to heat the 
same quantity of water, placed over the same fire, up to 
172 degrees, or 140 degrees above freezing ; that is, 140 
degrees have become latent, or hidden, in melting the 
snow. 

This same amount of heat may be given out again by 
placing the vessel of water out of doors to freeze. A 
thermometer will show that the water is growing colder 
by the escape of the heat, until freezing commences. Af- 
ter this it still continues to pass off, but the water becomes 
no colder until all is frozen, as it was only the latent heat 
of the water that was escaping. 

A simple and familiar experiment exhibits the same 
principle. Place a frozen apple, which thaw T s a little be- 
low freezing, in a vessel of ice-cold water. The latent 
heat of the water immediately passes into the apple and 
thaws it, and in an hour or two it will be found like a 
fresh apple and entirely free from frost ; but the latent 
heat having escaped from the water next the apple, a thick 
crust of ice is found to encase it. 

The amount of latent heat may be shown in still an- 
other way. Mix a pound of snow at 32 degrees, or at 
freezing, with a pound of water at 172 degrees. All will 
be melted, but the two pounds of water thus formed will 
12* 



274 HEAT. 

be as cold as the snow, showing that for melting it the 
140 degrees in the hot water were all made latent. 

ADVANTAGES OF LATENT HEAT. 

If no heat became latent by the conversion of ice and 
snow to water, no time would, of course, be required for 
the process, and thawing would be instantaneous. On 
the approach of warm weather, or at the very moment 
that the temperature of the air rose above freezing, snow 
and ice would all dissolve to water, and terrific floods and 
inundations would be the immediate consequence. 

LATENT HEAT OF STEAM. 

A still larger amount of latent heat is required for the 
conversion of water into steam ; for, again place the ves- 
sel of water with its thermometer on the fire, it will rise, 
as the heat of the water increases, to 212 degrees, and 
then commence boiling. During all this time it will now 
remain stationary at 212, until the water is all boiled away. 
This is found to require nearly five times the period need- 
ed to heat from freezing to boiling ; that is, nearly one 
thousand degrees of heat are made latent by the conver- 
sion of water into steam. 

When the steam is condensed again to water, this heat 
is given out. Hence the use made of steam conveyed in 
pipes for heating buildings, and for boiling large vats or 
tubs of water, by setting free this large amount of latent 
heat which the fire has imparted to it. 

GREEN AND DRY WOOD FOR FUEL. 

A great loss is often sustained in burning green wood 
for fuel, from an ignorance of the vast amount of latent 
heat consumed to drive off the water the wood contains. 
When perfectly green, it loses about one-third of its weight 



GREEN AND DRY WOOD FOR FUEL. 275 

by thorough seasoning, which is equal to about 25 cubic 
feet in every compact cord, or 156 imperial gallons. Now 
all this water must be evaporated before the wood is burn- 
ed. The heat thus made latent and lost, being five times 
as great as to heat the water to boiling, is equal to enough 
for boiling 780 imperial gallons in burning up every cord 
of green wood. The farmer, therefore, who burns 25 
green cords in a winter, loses heat enough to boil more 
than fifteen thousand gallons of water, which would be 
saved if his wood had been previously well seasoned un- 
der shelter. 

The loss in using green fuel is, however, sometimes 
overrated. It has been found by experiment that one 
pound of the best seasoned wood is sufficient to heat 27 
lbs. of water from the freezing to the boiling point.* 
This will be equal to heating and evaporating four pounds 
of water by every pound of wood. The 25 cubic feet of 
water, therefore, in every cord of green wood, weighing 
about 1,500 pounds, would require nearly 400 pounds of 
wood for its evaporation, or about one-seventh or one- 
eighth of a cord. Hence we may infer that seven cords 
of dry wood are about equal to eight cords of green. 
This imperfect estimate will apply only to the best hard 
wood, and will vary exceedingly with the different sorts 
of fuel ; the more porous the wood becomes, the greater 
will be the necessity for thorough seasoning. 



* The following results show the heating power of several combust- 
ibles : 
1 lb. of wood (seasoned, but still holding 20 per cent of water) 

raised from 32° to 212° 27 lbs. water. 

lib. ofalcohol 68 " 

1 lb. of charcoal 78 " 

1 lb. of oil or wax 90 " 

1 lb. of hydrogen 216 " 

It should be remembered that by ordinary modes of heating water, a 
very large proportion of the heat is wasted by passiDg up the chimney 
and into surrounding bodies, and the air. 



276 HEAT. 

Superficial observation often leads to very erroneous 
conclusions. Seasoned wood will sometimes burn with 
great rapidity, and, producing an intense heat for a short 
time, will favor an overestimate of its superiority. Green 
wood, on the other hand, kindles with difficulty, and 
burns slowly and for a long time; hence, where the 
draught of the chimney can not be controlled, it may be the 
most economical, because a less proportion of heat may 
be swept upward than by the more violent draught pro- 
duced from dry materials. Where the draught can be 
perfectly regulated, however, seasoned wood should be 
always used, for convenience and comfort, and for economy. 

Where wood is to be drawn to a distance, the preceding 
estimate shows that the conveyance of more than half a 
ton of water is avoided in every cord by seasoning. 



CHAPTER II. 

RADIATION OF HEAT. 

The passage of heat through conducting bodies has 
been already explained. There is another way in which it 
is transmitted, termed radiation, in which it is thrown off 
instantaneously in straight lines from hot bodies, in the 
same way that light is thrown off from a candle. A 
familiar instance is furnished by the common or open fire- 
place, before which the face may be roasted with the 
radiated heat, while the back is chilled with cold. A 
screen held in the hand will intercept this radiated heat, 
showing that it flies in right lines like the rays of light. 

Radiated heat is reflected by a polished metallic surface, 



RADIATION OF HEAT. 277 

in the same way that light is reflected by a looking-glass. 
A plate of bright tin held near the fire will not for a long 
time become hot, the heat being reflected from it without 
entering and heating it. But if it be blackened with 
smoke, it will no longer reflect, but absorb the heat, and 
consequently will speedily become hot. This experiment 
may be easily tried by placing a new tin cup containing 
water over a charcoal fire, which yields no smoke. The 
heat will be reflected into the fire by the tin, and the wa- 
ter will scarcely become warm. But if a few pine shav- 
ings be thrown on this fire, to smoke the surface of the tin, 
it will then absorb the heat rapidly, and soon begin to 
boil. This explains the reason that bread bakes more 
slowly in a new tin dish, and that a polished andiron be- 
fore a fire is long in becoming hot. 

A concave burning-mirror, which throws the rays of 
heat to a focus or point, may be made of sheet-tin, by 

Fi£. 294. 



beating it out concave so as to fit a regularly curved 
gauge. If a foot in diameter, and carefully made, it will 
condense the rays of heat so powerfully at the focus, when 
held several feet from the fire, as to set fire to a pine stick 
or to flash gunpowder (fig. 294). 

The reflection of radiated heat may be beautifully ex- 
hibited by using two such concave tin mirrors. Place 
them on a long table several feet apart, and ascertain the 
focus of each by means of the light of a candle. Then 
place in the focus of one a red-hot iron ball, or a small 
chafing-dish of burning charcoal. In the focus of the 



278 



HEAT. 



other place the wick of a candle with a small shaving of 
phosphorus in it. The heat will be reflected, as shown by 



Fig. 295. 




the dotted lines (fig. 295), and, setting fire to the phos- 
phorus, will light the candle. 

If a thermometer be placed in the focus of one mirror 
while the hot iron ball is in the other focus, it will rise 
rapidly ; but if a lump of ice be substituted for the ball, 
the thermometer will immediately sink, and will continue 
to do so until several degrees lower than the surrounding 
air ; because the thermometer radiates more heat to the 



mirrors 



, and then to the ice, than the ice returns. 



DEW AND FROST. 



All bodies are constantly radiating some heat, and if an 
equal amount is not returned by others, they grow colder, 
like the thermometer before the lump of ice. Hence the 
reason that on clear, frosty nights, objects at the surface 
of the earth become colder than the air that surrounds 
them. The heat is radiated into the clear space above 
without being returned ; plants, stones, and the soil thus 
become cooled down below freezing, and, coming in con- 
tact with the moisture of the air, it condenses on them 
and forms dew, or freezes into white frost. Clouds return 
or prevent the passage of the heat that is radiated, which 
is the reason there are no night-frosts in cloudy weather. 
A very thin covering, by intercepting the radiated heat, 
will often prevent serious injury to tender plants. Even 



FEOST IN VALLEYS. 279 

a sheet of thin muslin, stretched on pegs over garden 
vegetables, has afforded sufficient protection, when those 
around were destroyed. 

FROST IN VALLEYS. 

On hills, where the wind blows freely, it tends to re- 
store to plants the heat lost by radiation, which is the 
reason that hills are not so liable to sharp frosts as still 
valleys. When the air is cooled it becomes heavier, and, 
rolling down the sides of valleys, forms a lake of cold air 
at the bottom ; this adds to the liability of frosts in low 
places. The coldness is frequently still fuither increased 
by the dark and porous nature of the soil in low places 
radiating heat faster to the clear sky than the more com- 
pact upland soil. 

A knowledge of these properties teaches us the import- 
ance of selecting elevated places for fruit-trees, and all 
crops liable to be cut off by frost ; and it also explains 
the reason that the muck or peat of drained swamps is 
more subject to frosts than other land on the same level. 
Therefore, corn and other tender crops upon such porous 
soils must be of the earliest ripening kinds, so as to escape 
the frosts of spring by late planting, and those of autumn 
by early maturity. 

REMARKABLE EFFECTS OF HEAT ON WATER. 

The effects of heat and cold on water are of a very in- 
teresting character. "Without its expansion in freezing, 
the soil would not be pulverized by the frost of winter, 
but would be found hard, compact, and difficult to culti- 
vate in spring ; without its expansion into steam, the 
cities which are now springing up, and the continents that 
are becoming peopled, through the influence of rail-ways, 
steam-ships, and steam manufactures, would mostly re- 



280 HEAT. 

main unbroken forests ; without the crystallization of wa- 
ter, the beautiful protection of plants by a mantle of snow, 
in northern regions, would give place to frozen sterility ; 
without the conversion of heat to a latent state in melt- 
ing, the deepest snows would disappear in a moment from 
the earth, and cause disastrous floods ; without its con- 
version to a latent state in steam, the largest vessel of 
boiling water would instantly flash into vapor. All these 
facts show that an extraordinary wisdom and forethought 
planned these laws at the creation ; and even what appears 
at first glance as an almost accidental exception in the 
contraction of bodies by cold, and which causes ice to 
float upon water, preventing the entire masses of rivers 
and lakes from becoming permanently frozen, furnishes 
one out of an innumerable array of proofs of creative de- 
sign in fitting the earth for the comfort and sustenance of 
its inhabitants. 



APPENDIX. 

SIMPLE APPARATUS FOR ILLUSTRATING MECHANICAL ' 

PRINCIPLES. 

For the assistance of lecturers, teachers, and home students, the fol- 
lowing list is given of cheap and simple apparatus and materials for 
performing most of the experiments described in the first part of this 
work. These experiments, although simple, exhibit principles of much 
practical importance. 

1. Inertia apparatus, p. 12. The concave post or stand is sufficient, 
the snapping being done by the finger, although a spring-snap performs 
the experiment more perfectly. 

2. "Weight with two hooks and fine thread, p. 13. 

3. The inertia of falling hodies may be simply shown, and the pile- 
engine illustrated, by placing a large wooden peg or rod upright in a 
box of sand, and then dropping a weight upon its head at different 
heights, which will drive the rod into the sand more or less, according 
to the distance passed through by the falling weight. 

4. A straw-cutter, so made that the fly-wheel can be easily taken off, 
will show in a very striking manner the efficacy of this regulator of 
force. 

5. Two lead musket balls will exhibit the experiment in cohesion, 
p. 27. Balls or lead weights with hooks may be separated by sus- 
pending weights, to show the amount of force required to draAv them 
asunder. Metallic buttons or plates an inch in diameter, with hooks, 
will show the great strength needed to separate them when coated with 
grease, p. 27. 

6. Capillary tubes of different sizes, two straight small panes of glass, 
and a vessel of water, highly colored with cochineal or other dye, to ex- 
hibit capillary attraction. 

7. Glass tube, piece of bladder, and alcohol, for experiment described 
on p. 33. 

8. The cylinder for rolling up the inclined plane, represented by 
fig. 18, p. 34, may be very easily made by using a round pasteboard 
box a few inches in diameter, and securing a piece of lead inside by 
loops made with a needle and thread. The object shown by fig. 19 
may be cut in one piece out of a pine shingle, the centre rod being 
lengthwise with the grain ; the two extremities are shaved small, and 
wound with thick sheet-lead, and the whole then colored or painted a 

281 



282 APPENDIX. 

dark hue, to render the lead inconspicuous. The experiment with the 
penknives, p. 35, is very simple, care being taken to insert them low 
enough in the stick. 

9. Irregular pieces of board, variously perforated with holes, and fur- 
nished with loops to hang on a pin, may be used to determine the centre 
of gravity, according to the principle explained by fig. 21, p. 35. 

10. Portions of plank and blocks of wood, with the centre of gravity 
determined as in the last experiment, may have a plumb-line (which 
may be a thread and small perforated coin) attached to this centre, and 
then be placed on differently inclined surfaces, to show their upsetting 
just as this line of direction falls without the base. Toy-wagons, bought 
at the toyshops, may be variously loaded and used in experiments of 
this sort. 

11. Experiments with the lever of the first kind may be easily per- 
formed by the use of a flat wooden bar, two or three feet in length, 
marked into inches, and placed on a small three-cornered block as a 
fulcrum. Weights, such as are used for scales, may be variously 
placed upon the lever. Levers of the second and third kind, which are 
lifted instead of borne down, may have a cord attached to the point 
where the power is to be applied, running up over a pulley or wheel, 
with a weight suspended to the other end. 

12. An axle, furnished with wooden wheels with grooved edges, of 
different sizes, may be used to exhibit the principle of the wheel and 
axle, in connection with scale-weights that are furnished with hooks. 
The power of combined cog-wheels may be shown by a combination 
like that represented on p. 57, using weights for both cords. 

13. Interesting experiments with the inclined plane, at different de- 
grees of slope, by a contrivance similar to that represented by fig. 96, 
p. 83, with the addition of a small wheel at the upper side for a cord to 
pass over. This cord is fastened at one end to a light toy-wagon, run- 
ning up and down the plane, and at the other to a weight suspended 
perpendicularly just beyond the upper edge of the plaue. The wagon 
is variously loaded with weights, to counterpoise the suspended weight 
at different degrees of inclination. 

14. A lecturer may quickly demonstrate before a class the small in- 
crease in the length of a road, in consequence of a considerable curve 
to one side of a straight line (as shown by fig. 69), by using a cord for 
measuring, the diagram being marked on a board or the wall. 

15. A round stick of wood, and a long, wedge-shaped slip of paper, 
easily show the principle of fig. 75, p. 70. 

16. A cog-wheel with endless screw and winch (fig. 77, p. 71), exhibits 
distinctly the great power of the screw in this combination. 

17. Pine sticks, two feet long, and one-fourth to one-half inch through, 
of different shapes and sizes, supported at each end, and with weights 
hung at the middle till they break, may be made to illustrate the princi- 
ples described on pp. 80, 81. 

18. Some of the manciples of draught may be shown, and especially 



APPARATUS FOR EXPERIMENTS. 283 

those in relation to the different angles of inclination for hard and soft 
roads, by using a common spring-balance as a dynamometer, attached 
to a hand-wagon, and also to a sliding block of wood. 

19. Bent glass tubes, with arms of different sizes, to indicate the up- 
ward pressure of liquids, may be procured cheaply at glass-works. The 
experiment described by fig. 231, p. 204, may be rendered easy and inter- 
esting by purchasing a large and perfectly-working syringe, and attach- 
ing to its nose, by means of sealing wax, a slender glass tube two or 
three feet long. Fill the syringe with water, leaving the tube empty ; 
then, with the tube upright, drive the water up through it with the pis- 
ton of the syringe, and the increased weight felt on the piston as the 
column of water rises will be very evident. 

20. A hydrostatic bellows a foot in diameter, made by any good 
mechanic, will answer the purpose well, and exhibit an important prin- 
ciple! 

21. Specific gravities may be shown before a class by a common 
balance and a fine cotton or silk thread. 

22. A tin pail, with a hole half an inch or an inch in diameter at the 
bottom, will show the contracted stream which pours from it, p. 212. 
A short tin tube, with a slight flange at the upper end (quickly made 
by any tin-worker), fitted into this hole, will increase the discharge, as 
shown by figs. 236, 237, and the difference in time for emptying the ves- 
sel may be measured by a stop-watch. 

23. Archimedes' screw is readily made by winding a lead pipe rouud a 
wooden cylinder. 

24. A glass syphon, filled with cochineal water, shows distinctly the 
theory of waves, by blowing with the mouth into one end. 

25. Any vessel, filled with saud which has been heated over a fire, 
with rods of different substances, nearly of an equal size and length, 
and thrust with one end into the hot sand, in an inclined or nearly hori- 
zontal position, will exhibit the various conducting powers of these 
rods b) r melting pieces of wax or tallow placed on the ends most remote 
from the sand. 

26. The expansion by heat may be demonstrated by fitting an iron 
rod to a hole in sheet-iron ; on heating the bar it can not be made to 
enter. Or, if a hot iron ring be slipped on a tapering cold iron rod, it 
will contract on cooling so that the force of a man can not withdraw the 
rod. 

27. The rising and descending currents in a vessel of heating water 
are easily rendered visible by throwing into a glass vessel, or flask, over 
a lamp, particles of sawdust from any hard, greeu wood, whose specific 
gravity is about the same as that of water. 

28. Instrument figured on p. 265, for showing the principle of the 
steam-engine. 

29. Experiments in latent heat may be easily exhibited with the as- 
sistance of a common thermometer. 

30. Tin mirrors for showing radiation, p. 278. 



284 APPENDIX. 

DISCHARGE OF WATER THROUGH PIPES. 

Table showing the amount of water discharged per minute through 
an orifice one inch in diameter ; also through a tube one inch in diame- 
ter "and two inches long, according to experiment. To ascertain the 
amount in gallons, divide the cubic inches by 231. 

Height of head Amount discharged Amount discharged 

of water. through Orifice. through Tube. 

1 Paris foot* 2,722 cub. in. 3,539 cub. in. 

2 " 3,846 " 5,002 " 

3 " 4,710 " 6, 6 " 

4 " 5,436 " 7,070 " 

5 " 6,075 " 7,900 

6 " 6,654 " 8,654 

7 " 7,183 " 9,340 " 

8 " 7,672 " 9,975 " 

9 " 8,135 " 10,579 " 

10 " 8,574 " 11,151 " 

11 " 8,990 " 11,693 " 

12 " 9,384 " 12,o 5 " 

13 " 9,764 " 12,699 " 

14 " 10,130 " 13,177 " 

15 " 10,472 " 13,620 " 

VELOCITY OF WATER IN PIPES. 

The following table shows the height of a head of water required to 
overcome the friction in horizontal pipes 100 feet long, and to produce a 
certain velocity, according to Smeaton : 
Bore of 



Pipes. 


6 Inches. 


lfOOt. 


IVzfeet. 


2/eet. 


Zfeet. 


4feet 


5 feet. 


in. 


in. 


in. 


in. 


ft. 


in. 


ft. in. 


ft. 


in. 


ft. in. 


K 


4.5 


16.7 


35.1 


4 


9.7 


10 1.0 


17 


10.0 


28 0.2 


% 


3.0 


11.1 


23.3 


3 


2.5 


6 8.6 


11 


10.6 


18 8.1 


l 


2.2 


8.4 


17.5 


2 


4.9 


5 0.5 


8 


11.0 


14 0.0 


IK 


1.8 


6.7 


14.0 


1 


11.1 


4 0.4 


7 


1.6 


11 2.5 


IK 


1.5 


5.6 


11.7 


1 


7.2 


3 4.3 


5 


11.3 


9 4.1 


1% 


1.3 


4.8 


10.0 


1 


4.5 


2 10.6 


5 


1.1 


8 0.1 


2 


1.1 


4.2 


8.7 


1 


2.4 


2 6.2 


4 


5.5 


7 0.0 


2U 


1.0 


3.7 


7.8 


1 


0.8 


2 9.9 


3 


11.6 


6 2.7 


2K 


0.9 


3.3 


7.0 





11.5 


2 0.2 


3 


6.8 


5 7.2 


3 


0.7 


2.8 


5.0 





9.6 


1 8.2 


2 


11.7 


4 8.0 


3K 


0.6 


2.4 


5.0 





8.2 


1 5.3 


2 


6.6 


4 0.0 


4 


0.6 


2.1 


4.4 





7.2 


1 3.1 


2 


2.7 


3 6.0 



* A Paris foot is about 12 4-5 U. S. inches, and 15 Paris feet are about 
16 U. S. feet. 



RULE FOR THE DISCHARGE OF WATER. 285 

Look for the velocity of the water per second in the pipe, in the up- 
per line ; and in the column beneath it, and opposite the given diameter 
of the pipe, is the height of the columu or head required to obtain the 
required velocity. 

To find the quantity of water discharged each minute, multiply the 
velocity by 12, which will give the inches per second ; then multiply 
this product by 60, which will give the inches per minute ; then, to 
change these cylindrical inches into cubic inches, multiply by 4 and 
divide by 5.* Divide the cubic inches by 231, and the result will be 
gallons. 

Bj T comparing this table with the next preceding, we shall perceive 
that the water flows from three to four times as fast through the tube 
two inches long, as through a tube one hundred feet long, the diameter 
of the tube and the head of water being the same. 



RULE FOR THE DISCHARGE OF WATER. 

The following general formula or rule, applicable to different cases, 
has been furnished by a practical engineer. It may be useful in ascer- 
taining the quantity required to fill the driving pipe of a water-ram, and 
for various other purposes occasionally occurring in practice. 



Let A represent the fountain or reservoir from which water is to be 
conveyed to the trough B through the pipe L. Let // be the height of 
the surface of the water in the reservoir, above the place of discharge, 
L the length of the tube in feet, and let D be the diameter of the tube 
in the smallest part. It is required to find the quantity, §, which will 
be discharged in a second of time. The length and height being given 
in feet, and the diameter of the tube in inches, the formula, when the 
quantity is required in gallons, is as follows : 

Q = 0.608 V^ D l) 



• This gives the cubic inches very nearly ; but, to be more accurate, multiply 
the decimal .7854, which represents the difference between the area of a square 
and of a circle. 



286 



APPENDIX. 



In order to make the above formula more intelligible : 
Let L = SO rods or 1320 feet. 
" H = 50 feet, 
" D = 2 inches. 
" Q = gallons. 

Then Q =0.60S i / (32x-,f|o) = 0.67; or, the same maybe thus ex- 
pressed in words : 

Divide the height (50) by the length (1320) ; multiply the quotient by 
the fifth power of the diameter (fifth power of 2 = 32) ; extract the 
square root of the product, which, being multiplied by 0.608, will give 
(0.67) the number of gallons the tube will discharge in one second ; 
which, in this case, is 40 gallons in one minute. 

VELOCITY OF WATER IN TILE DRAINS. 



An acre of laud in a wet time contains about one thousand spare 
hogsheads of water. An underdrain will carry oft' from a strip of land 
about two rods wide, and one eighty rods long will drain an acre. The 
following table will show the size of the tile required to drain an acre in 
two days' time, (the longest admissible), at different rates of descent, or 
the size for any larger area : 



Rate of Descent. 

1 foot in 100 

1 foot in 50 

1 foot in 20 

1 foot in 10 

1 foot in 100 

1 foot in 50 

1 foot in 20 

1 foot in 10 

1 foot in 100 

1 foot in 50 

1 foot in 20 

1 foot in 10 

A deduction of one-third to one-half must be made for the roughness 
of the tile or imperfection in laying. The drains must be of some 
length, to give the water velocity, and these numbers do not, therefore, 
apply to very short drains. 



iameter of Bore 


2 iuches. 


2 inches. 


2 inches. 


2 inches. 


3 inches. 


3 inches. 


3 inches. 


3 inches. 


4 inches. 


4 inches. 


4 inches. 


4 inches. 



Velocity of 


Hogsheads 


Current per 


discharged 


second. 


in 24 hours. 


22 inches. 


400 


32 inches. 


560 


51 inches. 


900 


73 inches. 


1290 


27 inches. 


1170 


38 inches. 


1640 


67 inches. 


3100 


84 inches. 


3600 


32 inches. 


2500 


45 inches. 


3500 


72 inches. 


5600 


100 inches. 


7800 



GLOSSARY 

OF TERMS USED IN MECHANICS AND FARM MACHINERY. 



Axis, a real or imaginary line, passing through a body, on which it is 
supposed to revolve. 

Axle or axle-tree, the bar of metal or timber, on the ends of which 
the wheels of a carriage or wagon or other wheels revolve. 

Babbett metal, an alloy, usually of tin and copper, for casing the 
supports of journals, either for repair, or for easier running. 

Back furrow, to throw the earth from two plow -furrows together. 

Ball-cock, a self-regulating stop-cock, closed or opened by the rising 
or falling of a floating hollow ball. 

Ball-valve, a valve consisting of a loose ball, fitting closely, pre- 
vented from moving beyond a certain limit. 

Band-wheel, a wheel in machinery on which a band or belt runs. 

Beam, the main lever of a steam-engine, turning on the centre, with 
the piston rod at one end, and the working-rod at the other. Also, the 
main timber or bar of a plow. 

Bearing, the part of a shaft or spindle which is in contact with the 
supports. 

Bed, the foundation on which a fixed machine rests, as "the bed of an 
engine." 

Bell-crank, a crank resembling that by which the direction of a bell- 
wire is changed. 

Bevel-gear, the gearing of cog-wheels placed obliquely together, or 
with the two axes forming an angle. 

Bolster, the cross-bar of a wagon, resting on the axle, holding the 
box, and through which the king-bolt passes. 

Brake, a lever or other contrivance used for retarding the motion of 
a wheel by friction against it. 

Breast-wheel, a water wheel where the current is delivered upon it 
about one-half or two-thirds its height, which distinguishes it from un- 
dershot and overshot wheels. 

Bridle, the forward iron on the beam of a plow, to which the team 
is attached. 

Brush-weeel, a wheel in light machinery, turned by friction merely, 
instead of cogs ; bristles or brushes being often fixed to them to increase 
the friction of their pressing surfaces. 

Bush, the hollow box fitted into the centre of a wheel to take the 
bearing of an axle or journal. 
287 



288 GLOSSAET. 

Cam, the projecting part of an eccentric or wavy wheel, to produce 
alternate or reciprocating motion. 

Cant-hook, a wooden lever with an iron hook near one end, used for 
moving heavy articles, particularly saw-logs, etc. The end of the lever 
is usually placed on the fulcrum, and the hook is fixed into the weight, 
making it a lever of the second kind. 

Capillary attraction, the attraction which causes liquids to rise in 
very small tubes, or which retains water among sand and the particle? 
of soil. 

Centre of gravity, that point in a body or mass of matter, arouno 
which all parts exactly balance each other. 

Centrifugal force, tending to fly from the centre, as the stone from 
a sling. 

Centripetal force, drawing towards the centre, like the cord of a 
sling. 

Chamfer, a slope, channel, or groove, cut in wood or metal. 

Chase, a wide groove. 

Chilled, applied to cast-iron rendered harder by casting the melted 
metal against cold metal in the mould, for rendering certain parts harder 
which are most liable to become worn. 

Chine, the ends of the staves of a barrel, outside the heads. 

Clamp, a cross-bar used to give additional strength, or to prevent 
warping. Also, a piece of metal or wood, generally resembling in shape 
the letter U, furnished with a screw, to fasten objects to a table or other 
fixed bodies, or to each other. 

Cleat, a piece of wood nailed across, to give strength or security. 

Clevis, a draught iron, usually somewhat in the form of a bow or let- 
ter U, placed on the forward end of a plow-beam for draught, or for 
similar purposes. 

Click, a pawl, a latch, or the ratchet of a wheel. 

Cog, the tooth or projection of a cog-wheel. 

Collar, a metal ring around the end of a cylinder of wood to prevent 
splitting, or a ring around a piston or a journal, for securing tightness 
or steadiness. 

Colter or Coulter, the upright cutting iron of a plow. 

Compass, an instrument for describing circles, measuring distances^ etc. 

Counter-sink, a cavity made to receive the head of a screw. 

Coupling-box, a contrivance for connecting shafts, or throwing 
wheels in and out of gear. 

Crab, a small portable crane. 

Cradle, a scythe with fingers, for cutting grain by hand. 

Crane, a machine for raising weights and then swinging them side- 
wise ; generally made by attaching a pulley to a swinging bar or frame. 

Crank, an axle with a crooked portion for changing a rotary to an 
alternate motion, or the reverse. A three-throw crank has three bends, 
for driving three pumps, each stroke separated from the others by the 



GLOSSARY. 289 

third of a revolution, thus making a regular and uniform application of 
the force. 

Cross-cut Saw, a large saw worked by a man at each end, for cutting 
logs. 

Cutter-bar, the cutting apparatus of a mowing or reaping machine. 

Cycloid, a curve made by any point in a circle rolling on a straight 
line, and marking the curve on a plane surface at the side of the circle. 
A rail driven in the rim of a wagon-wheel, driven through a snow bank, 
will mark a cycloid on the snow. An epicycloid is made by a similar 
revolution of a circle, rolling on the circumference of another circle, 
externally or internally. 

Dead centre, a centre which does not revolve. 

Dead furrow, the furrow where the plow throws the earth in oppo- 
site directions, or where the furrows meet in plowing a strip of land. 

Derrick, a pole or upright timber for supporting a crane, used in lift- 
ing heavy materials in building and for other purposes. 

Dog, an iron catch or clutch, driven into the end of a saw-log, to hold 
it in a fixed position while sawing. 

Double-tree, the central wbiffle-tree of a two-horse set. 

Dowel, a short iron or wooden pin to join two pieces of timber, pro- 
tecting from one timber into a hole in the corresponding one. A 
familiar example occurs in the manner in which a cooper secures two or 
more boards in forming the head of a cask. 

Draught, Angle of, the angle made by a line of draught with a line 
drawn on ,he surface over which the body is drawn. 

Dredge, or Dredging Machine, a machine for scooping up mud or 
earth from under water; for clearing the channels of canals, rivers, and 
harbors. 

Drill, a furrow for the reception of seed, or a row of growing plants ; 
also a machine for sowing seed in continuous rows. 

Driving-wheel, the wheel of a mowing or reaping machine, which 
runs on the ground, and propels the gearing. 

Drum, a revolving cylinder, around which belts or endless straps are 
passed, to communicate motion. 

Dynamics, the science of motion and forces. 

Dynamometer, an instrument for measuring forces, applied to plows, 
mowing machines, thrashing machines, etc., to show the amount of 
force required to work them. 

Eccentric, out of centre; applied to wheels, discs, or circles, with 
the axle out of centre, to create reciprocating motion. Eccentric rod is 
the rod that transmits the motion of the eccentric wheel. 

Elevator, an endless revolving leather strap, set with sheet-iron 
boxes or cups, for raising grain. The term is also applied to buildings 
into which grain is thus elevated and stored. 

Emery wheel, a wheel set with emery at the circumference, for 
grinding or polishing metals. 

Endless chain, a chain with the ends connected together, running on 

in ' 



290 GLOSSARY. 

two drums or cylinders ; as in the endless chain or tread-powers to 
thrashing machines. 

Endless screw, a screw working in a toothed wheel or cog-wheel, 
and imparting a motion to the wheel equal to the advance of one tooth 
to each revolution of the screw. 

Epicycloid, see Cycloid. 

Epicycloidal wheel, a wheel with cogs on its interior rim, fitting 
into another cog-wheel precisely one-half its diameter, for converting 
circular into alternate motion ; any point in the circumference of the 
smaller wheel, while in motion, describing a straight line. 

Evener, the central or larger whiffle-tree of a set of whiffie-trees for 
two horses, called also a double-tree. 

Fan, the vane of a wind-mill, to keep the sails facing the wind. 

Feather, the thin cutting part of a plowshare, on the right-hand side. 

Felloe, or Felly, the circumference or rim of a wheel, or a segment 
of it, into which the spokes are inserted. 

Ferrule, a ring or hand on the end of a wooden rod or bar, to pre- 
vent splitting. 

Female screw, a hole cut with the threads of a screw, into which a 
screw fits. 

Finger-bar, that portion of the cutting-bar of a mowing or reaping 
machine, in which the knife-bar works. 

Flange, a projection from the end of a pipe or from any piece of 
mechanism, so as to screw to another part ; a term also applied to the 
projection of a car-wheel to keep it from running off the rail. 

Flash- wheel, a water-wheel used for elevating water, resembling a 
breast-wheel with a reversed motion. 

Float-board, one of the boards forming the exterior of a water- 
wheel, against which the stream of water dashes. 

Flume, the water passage of a mill, usually a box of plank. 

Fly-wheel, a wheel with a heavy rim, for retaining inertia and equal- 
izing the motion of machinery. 

Foot-valve, a valve in a steam-engine, opening from the condenser 
towards the air-pump. 

Force-pump, or Forcing-pump, a pump with a solid piston, which 
drives instead of sucking water. 

Friction-wheel, made by two wheels overlapping each other, and 
bearing between them the axle or journal of another wheel, thus dimin- 
ishing the friction of the latter. 

Fulcrum, a support ; applied to the support used for the lever, in 
raising weights. 

Furrow slice, the strip of earth thrown out by the plow at a passing. 

Furrows, plat and lapping; when the slice is laid flat or level, and 
when the edge of one overlaps the preceding, respectively. 

Gang-plow, a compound plow made of a series of plows running side 
by side. 

Gavel, a sheaf of grain reaped but not bound. 



GLOSSARY. 291 

Gearing, a series of cog-wheels working together. 

Governor, a self-regulator of a steam-engine, so constructed that 
centrifugal force throws up weights When the engine runs too fast, and 
partly closes the admission pipe of steam ; and, dropping again when it 
runs too slow, opens the steam pipe. 

Gravitation, the attraction between bodies in mass, as distinguished 
from cohesion between the particles; the force which causes bodies to fall 
by the attraction of the earth. 

Guard, one of the fingers in the cutting apparatus of a mowing or 
reaping machine, for protecting the knives from injury from external ob- 
jects. Open Guard has an opening above the knives, to prevent clog- 
ging. 

Hat-tedder, a niachiue for spreading and turning hay. • 

Header, a reaping machine which cuts the heads of the grain and 
leaves most of the straw standing. 

Head-land, the strip or border of unplowed land left at the ends of 
the furrows. 

Hound, the forward portion of a wagon, to which the tongue is at- 
tached. 

Hydraulic Ram, see Ram. 

Hydraulics, the science of water in motion, or the laws of motion 
and force as applied to running water, and to machinery driven by it. 

Hydrodynamics, the laws of motion and force, as applied to liquids, 
both in motion and at rest, and embracing Hydraulics and Hydrostatics. 

Inclined plane, a plane or surface deviating more or less from a 
level. if 

Inertia, the property or force of matter by which it retains its state 
of motion or rest, — requiring force to start a body at rest or to stop one 
in motion. 

Jack, an engine or machine for raising heavy weights. 

Jack-screw, a strong iron screw for raising timbers, buildings, etc. 

Journal, the portion of a shaft or axle which revolves on a support. 

Kerf, the opeuing or slit made by the passage of a saw. 

Key, a wedge of wood or metal driven iuto a mortise or opening, to 
secure two parts together. 

Knee-joint, or Toggle-joint, a contrivance for exerting power or 
pressure, by straightening a double bar with a joint like that of the knee. 

Land, a term applied to the oblong portion of a field around which 
the team passes in plowing, the field being usually divided into several 
lands for this purpose. The term is also applied to the side of a plow 
opposite the mould board, and a plow is said to run to land when it takes 
too wide a furrow-slice. 

Land-side, the side of that portion of a plow which runs in the 
soil, opposite the mould-board, and next the unplowed portion of ground. 

Lantern-wheel, a pinion made of two small wheels connected by 
parallel rods which form the teeth. 



292 GLOSSARY. 

Lever, a bar or rod for raising weights, resting on a point called a 
fulcrum. 

Lever-power, see Sweep-power. 

Male screw, a screw with a spiral thread, fitting into a hole with cor- 
responding threads called a female screw. 

Mechanical powers, the simple machines or elements of machinery, 
consisting essentially of the Lever and Inclined Plane ; the lever com- 
prising the Wheel and Axle and the Pulley, and the inclined plane com- 
prising the Wedge and the Screw. 

Mash, or Mesh, to interlock, as the teeth of cog-wheels. 

Mechanics, the science that treats of forces and powers, and their 
action on bodies, and particularly as applied to the construction of ma- 
chines. 

Mitre, to cut to an angle of 45 degrees, so that two pieces joined 
shall make a right angle. 

Momentum, impetus ; the force of a moving body. 

Monkey, an apparatus for disengaging and securing again the ram of 
a pile-engine. 

Mortise, a hole cut to receive the end or tenon of another piece. 

Nut, a piece of iron furnished with a screw-hole, used on the end of a 
screw for securing the parts of machinery. 

Overshot wheel, a water-wheel, the circumference of which is fur- 
nished with cavities or buckets, into which the stream of water is deliv- 
ered at the top, turning the wheel by its weight. 

Pall, or Pawl, the catch of a ratchet-wheel ; a click. 

Pent-stock, an upright flume. 

Perambulator, a measurer of distances, consisting of a wheel, and 
index to show by wheelwork the number of its turns. 

Percussion, Centre op, that point of a moving body at which its im- 
petus is supposed to be concentrated. 

Pile-driver, or Pile-engine, an engine for driving piles into the 
ground, effected by repeatedly dropping a heavy weight on the heads of 
the piles ; used mostly in swamp or water when the bottom is mud. 

Pinion, a small-toothed wheel, working in the teeth of a larger one. 

Pitch, the distance between the centres of two contiguous cog-wheels. 

Pitch line, the circle, parallel with the circumference, which passes 
through the centres of the teeth of a wheel. 

Pitman, a rod connected with a wheel or crank, to change rotary to 
reciprocating motion, or the reverse. 

Planet-wheels, two elliptical wheels connected by teeth running 
into each other, and revolving on their foci. 

Plow-beam, the main timber of a plow, by which it is drawn. 

Plow-share, the front part beneath the soil, which performs the cut- 
ting — sometimes called plow-s7we, or plow-point. 

Plunger, the piston of a forcing pump. 

Pneumatics, the science treating of the mechanical properties of air. 

Pole, the tongue of a reaping or other machine. 



GLOSSARY. 293 

Power, the moving force of a machine, as opposed to the weight, 
load, or resistance of the substance wrought upon ; also called prime 
mover. 

Projectile, a body thrown through the air. 

Pulley, one of the mechanical powers, consisting of a grooved wheel 
called the sheave, over which a rope passes ; the box in which the wheel 
is set is called the block. The term is also applied to a fixed wheel over 
which a band or rope passes. 

Pump, a hydraulic machine for raising water; or one for withdrawing 
air. The handle is called the brake. 

Quantity of motion, the velocity of a moving body multiplied by its 
mass. 

Rabbet, to pare down the edge of a board or timber. 

Rack, a straight bar cut with teeth or cogs, wprking into a correspond- 
ing cog-wheel or pinion which drives or follows it. 

Rag-wheel, a wheel with teeth or notches, on which nn endless or re- 
volving chain usually runs. Also applied to a ratchet wheel. 

Rake-head, the cross-bar of a rake, which holds the teeth. 

Ram, Hydraulic ram, or Water-ram, a hydraulic machine or engine 
for raising water to a height several times greater than that of the head 
of water, by employing the momentum of the descending current in 
successive beats or strokes. 

Ratchet-wheel, a wheel cut with teeth like those of a saw, against 
which a click or ratchet presses, admitting free motion to the wheel in 
one direction, but insuring it against reverse motion. 

Reach, the bar which connects the forward and rear axles of a wagon 
or carriage. 

Rea.m, to bevel out a hole. 

Reciprocating motion, alternate motion, or a movement backwards 
and forwards in the same path. 

Reel, the revolving frame of a reaping machine, to throw the stand- 
ing grain towards the knives. 

Resolution of forces, dividing a force iuto two or more forces act- 
ing in different directions ; rendering a compound force into its several 
simple forces. 

Resultant, a force produced by the combination of two or more 
forces. 

Safety valve, a valve opening outwards from a steam boiler, and 
kept down by a weight, permitting the escape of steam when the press- 
ure reaches a certain point, regulated by the degree of weight. The 
term also applies to a valve opening inwards, and similarly regulated, to 
prevent the pressure of the atmosphere from crushing in the boiler when 
the steam cools and leaves a vacuum. 

Scoop- wheel, a water-wheel with scoops or buckets around it, against 
which the current dashes. 

Screw-bolt, a bolt secured by a screw, or with a screw cut upon it. 

Screw-propeller, an instrument for driving a vessel, by means of 



294 GLOSSAEY. 

blades twisted like a screw, revolving beneath the water, the axis being 
parallel with the keel. 

Section, one of the knives or blades on the cutter-bar of a mowing 
machine. 

Self-raker, a contrivance attached to a reaping machine, to throw 
off the cut grain in gavels, to obviate raking off by hand. 

Shears, or Sheers, two poles lashed together like the letter X, for 
placing under heavy poles, etc., in raisiug them; also to single vertical 
poles supporting pulleys, for a similar purpose. 

Sheave, the wheel of a pulley set in a block. 

Shoot, or Shute, a passage-way down which grain, hay, or straw, is 
slid or thrown. 

Side-draught, the side pressure of a machine on the team which 
draws it, as distinguished.from centre draught. 

Single-tree, a single whiffle-tree, the cross-bar to which the traces of 
a horse are attached, as distinguished from a double-tree, or two-horse 
whiffle-tree. 

Siphon, or Syphon, a bent tube for drawing off liquids ; the column 
of liquid in the outer or longer leg overbalancing the inner column, 
and producing a current. 

Skein, the iron casing of a wagon-axle on which the wheel runs. 

Skim-coulter, a coulter of a plow so constructed as to pare the sur- 
face before the mould-board. 

Skim-plow, the small forward mould-board of a double Michigan or 
Sod-and-subsoil plow. 

Slide-rest, the rest or support of the chisel in a turning lathe, made 
to slide along the frame for cutting successively the different parts of the 
work. 

Slot, a slit or oblong aperture in any part of a machine, to admit an- 
other part. 

Snath, the handle or bar to which the blade of a scythe is attached. 

Sod, the slice of earth cut by the passing of a plow. 

Sole, the bottom plate under a horse-shoe tile, in draining. 

Spindle, a small axle in machinery, as distinguished from a shaft or 
large axle. 

Spirit-level, a glass tube containing alcohol with an air-bubble, her- 
metically sealed at both ends, the position of the bubble at the middle 
showing the tube to be level. 

Spur-wheel, or pinion, a cog-wheel with teeth parallel to the axle. 

Standard, an upright supporting timber ; the front upright bar in a 
plow to which the mould-board is fastened. 

Steam chest, a box attached to the c} 7 linder of a steam-engine, in 
which the sliding valves work. 

Stirrup, an iron band encasing a wooden bar, for attaching to some 
other part. 

Stud, a short, stout support. 



GLOSSARY. 295 

Subsoil-plow, a plow running below the furrow of a common plow, 
for breaking up or loosening the subsoil or lower soil of a field. 

Swage, to give shape to a substance by stamping with a die. 

Sweep-power, a horse-power for driving thrashing and other ma- 
chines, where the horses arc attached to a pole and walk in a circle. 

Swingle-tree, also called" swing-tree, single-tree, whipple-tree, 
and whiffle-tree ; the cross-bar to which traces are attached. 

Swing-plow, a plow with no wheel under the beam. 

Swivel, a ring and axis in a chain, to admit of its turning. 

Swivel bridge, a bridge which turns round sideways on its centre. 

Swivel plow, a side-hill plow, or a plow with a reversible mould-board. 

Tackle, a pulley, or machine with ropes and blocks for raising heavy 
weights. 

Tail-race, the channel which carries off the water below a water 
wheel. 

Tedder, a machine for turning and spreading hay. 

Thill, one of the shafts of a wagon between which the horse is put 
— often corrupted to Fill. 

Throttle- valve, a valve which turns at its centre on an axis — gener- 
ally used to regulate the supply of steam to the cylinder of a steam-en- 
gine. 

Thumb-screw, a screw with its head flattened in the direction of its 
length, so as to be turned with the thumb and finger. 

Tide- wheel, a wheel adapted to currents flowing both ways — the float- 
boards pointing from the centre. 

Tine, the tooth or prong of a fork. 

Tire, the iron band which binds together the fellies of a wheel. 

Toggle-joint, or knee-joint, a mechanical power exerted by straight- 
ening a double bar with a hinge at the middle or connection. 

Torsion, the act of twisting by the application of lateral force. The 
force of torsion is the elasticity of a twisted body, 

Track-cleaner, an attachment to a mowing machine, to throw the 
cut grass away from that which is uncut. 

Traction, Angle of, the angle between the line of draught and any 
given plane, as that of the earth's surface. 

Trammel, an instrument used by carpenters for drawing an ellipse. 

Tread-power, a machine on which the horse or other animal working 
it walks. It may be either a horizontal or slightly inclined wheel ; or 
an endless-chain power, the term being more frequently applied to the 
latter. 

Trench-plow, a plow cutting deep furrows and bringing the subsoil 
up to the surface; as distinguished from a subsoil plow, which only 
loosens the subsoil and leaves it below the surface. 

Trundle-head, a wheel turning a mill-stone. 

Tub-wheel, a horizontal water-wheel, driven by the percussion of the 
stream against its floats, and not submerged in water. 



296 GLOSSARY. 



3 the 



Tumbler, a latch in a lock, which, by means of a spring, detains 
bolt in its place until lifted by the key. 

Tumbling rod, the rod which connects the motion of a horse-power 
with that of a thrashing or other machine. 

Turbine wheel, a horizontal water-wheel, so constructed that the 
current strikes all the floats or buckets around the circumference at the 
same time, thus imparting to it great power for its size. It is sub- 
merged, the water escaping towards the centre and below, or above and 
below together. 

Undershot wheel, a water-wheel moved by the current striking 
against the lower portion of its circumference. 

Universal joint, a connecting joint between two rods, consisting of 
a sort of double hinge, admitting motion in any direction. 

Valve, a lid for closing an aperture or passage, so as to open only in 
one direction. 

Velocity, speed or swiftness; which may be uniform, or equal 
throughout ; accelerated, or increasing ; or retarded, or rendered slower. 

Virtual velocities, Principle of, that by which certain powers are 
equal to each other, where the force and space moved over, whatever 
these may be, are the same when multiplied together. 

Washer, a circular piece of metal, pasteboard, or leather, placed be- 
low a screw-head, or nut, or within a linch-pin, for protection. 

Water-ram, see Ram. 

Whiffle-tree, or Whipple-tree, the cross-bar to which the traces 
of a horse are attached ; see Single-tree. 

Whip-saw, a large saw, worked by a man at one end, with a wooden 
spring at the other ; a cross-cut saw. 

Winch, a bent handle or right-angled lever, for turning a wheel or 
grindstone, or producing rotary motion for other purposes. 

Windlass, a machine for raising heavy weights, by the winding of a 
rope or chain on a horizontal axle, and turned by a winch or by levers. 

Winrow, or Windrow, the ridge of hay raked up on a meadow. 

Wrest, a partition which determines the form of the bucket in an 
overshot wheel. 



INDEX 



Air, Pressure of 239 

u Mode of weighing 239 

" Pump 240 

" Hand fastened, by 241 

" Motion of. 245 

" Resistance of. 247 

Alden's Cultivator 14G 

Allen's Farm Mill 195 

Altitudes measured by the Barome- 
ter 243 

American Hay-tedding Machine 165 

Appai-atus for Experiments 281 

Aqueducts of the Romans 199 

Archimedean Root Washer 193 

" Screw 217 

Archimedes, would move the earth 

with a lever 55 

Artesian Springs and wells 201 

Atmosphere, Height and Weight 

of 239, 241 



B 



Bags, How to carry 41 

Balance, a lever 47 

Balls, Why they roll easily 38 

Barometer 241 

Bars of wood, Strength of. 79 

Beardsley's Hay Elevator 177 

Bellows, Hydrostatic 204 

Bevel Wheels or Bevel Gear GO 

Billings' Corn Planter 155 

Binders for Reaping Machines 163 

Boat, Compound motion of. 20 

Broadcast Sower, Seymour's . .154 

Brown's Wind-mill 251 

Brush Harrow 142 

Buckeye Mower 159 

Bullard's Hay-tedding Machine 165 

Bulk of a ton of different substances. 210 
Burrairs Corn-sheller 191 



C 

Capillary attraction 31 

" " its great import- 
ance 32 

Cayuga Chief Mower 160 

" " Dropper 162 

Cements, Effects of. 28 

Centre of Gravity 34 

" " curious examples 

of ) 35 

" how determined 35 

Centrifugal Force 21 

Chain Pump 221 

Cheese Press 72 

." " Dick's 74 

11 " Kendall's 73 

Chimney Currents 253 

" Caps 254 

Chimneys, Construction of 254 

" To prevent smoking 256 

Churn with fly-wheel 17 

" worked by dog-power 191 

Cistern Pumps 219 

Cisterns, To calculate contents of. .237 

" Proper sizes for 238 

Clod Crusher .149 

" " Croskill's and Ameri- 
can 150,151 

Cog, Hunting 60 

Cogs, Form of 58 

" and Cog-wheels 58 

Cohesion, Attraction of 27 

" between lead balls 27 

" weak in liquids 31 

Complex Machines, objectionable.. 116 

Compound motion 19 

" " How to calculate. 20 

Comstock's Rotary Spader. . . .148, 117 

Conducting power of bodies 260 

" " liquids 261 

Corn Planter, Billings' 155 

" Shelter, 'Burrairs 191 



297 



Q* 



298 



INDEX. 



Corn Sheller, Horse-power 192 

Richards' 192 

Corn Planters 155 

Cost of Implements and Machines. 117 

Cotton Gin, Emery's 196 

Coulter for Plows 127 

Crested Furrow-slice 126 

Crosskill's Clod-crusher 150 

Crow-bar, a simple power 43 

Crown Wheels 60 

Cubic foot of different substances, 

Weight of 210 

Cultivator, or Horse-hoe 145 

Claw-toothed 146 

Alden's Thill 146 

" Duck-foot 146 

" Two-horse 148 

" Harrington's 157 

Cutter for the Plow 127 

" Bar in Mowers and Reapers. 158 

B 

Dederick's Hay-press 185 

" Capstan 185 

Deep-tiller Plow, Holbrook's 126 

Deep Wells, Pump for 220 

Dew and Frost 278 

Discharge of water through pipes.. 284 

" " Rule for 2S5 

Ditches, Velocity of water in. .214, 286 
" Leveling instruments for.. 115 

Dog-power Churn 191 

Draught, Combined 96 

Draught of wheels, explained 37 

" Line of 95 

" Principles of 93 

" How to measure 94 

" of Plows 95 

Drilling wheat 153 

Drills, Hand 157 

Drive-pump 220 

Dropper, attachment to reapers 162 

Dynamometer, applied to roads S5 

" Construction and use 

of 98 

" Self-recording 101 

" Waterman's 102 

■ " for rotary motion... 106 

E 

Elevators for Hay 173 

Emerson's Chimney Cap 255 



Emery's Horse-powers 1S8 

Cotton Gin 196 

Empire Wind-mill 251 

Endless-chain power 1S8, 189 

Engine, Garden. . : 230 

Experiments, apparatus for 281 

F 

Falling Bodies, Velocity of 23 

" " Resistance of air on 25 

" " in vacuo 25 

Farm, Seventy-thousand-acre 8 

" implements, Construction 

and use of. 115 

" implements, Cost of 117 

" mills 195 

Finger-bar in mowers and reapers.. 15S 

Flail, Old sort 187 

" Estimate of comparative work 

with 187 

Flash-wheel 231 

Flea, power of leaping 115 

Fly-wheel 16 

" used on horse-pump 16 

Forcing-pump 223 

Fork Handles, Proper form of 76 

Forsman's Farm Mill .195 

Friction '. 81 

" Nature of 82 

" How to Measure 83 

" not influenced by velocity. 88 

" of axles 89 

" of wheels . 90 

" Lubricating substances for. 91 

" Advantages of 92 

Frost and Dew 278 

" in valleys 279 

Fuel, Green wood for 275 

Furrow-slice, Crested 126 

Furrows, Lapping and flat 127 



G 



Galileo's experiment on falling bod- 
ies 26 

Garden Engine 230 

Garrett's Horse-hoe 147 

Geddes' Harrow 143 

Gladding's Hay -fork 175 

Glossary of terms 287 

Gravitation 23 

Gravity, Centre of. 34 



INDEX. 



299 



Gravity, Specific, how measured.. .208 
" "of different sub- 
stances 200 

Green wood for fuel , 274 

H 

Hand-drills 157 

" rakes, sulky 160 

Harrington' s Seed sower 157 

" Cultivator 157 

Harrow, Norwegian 144 

" Morgan 144 

" Scotch, or square 143 

Harvester, Marsh's 163 

Hay-forks, Horse. 173 

" carriers 180 

" loaders 186 

" rake, Revolving 168 

" " Warner's 169 

" rakes 166 

" Simple 167 

" stacking machine 184 

" tedder, Bullard's 165 

" " American.. 166 

" presses 184 

" sweep 171 

Headers 163 

Heat, Properties of. 260 

" Expansion by 263, 271 

" Latent 273 

" Radiation of 276 

Hicks' Hay -carrier 180 

High pressure steam-engines 269 

Hoe-handle, Proper form of 77 

Holbrook's Plow 125 

" Swivel or side-hill Plow.133 
Horse, day's work at different de- 
grees of speed 110 

" hoe, Garrett's 147 

" power, Estimating 109 

" Hay-forks, Operation of 174 

fork, Gladding's 175 

" " Palmer's 176 

" " Myers' 177 

" " Beardsley's 177 

" " Raymond's 178 

" " Harpoon 179 

" Walker's 179 

" Sprout's 179 

Hydraulic Ram 226 

" " Regulating 227 

Hydrostatic Paradox 203 



Hydrostatic Bellows 204 

" Press 203 

Hydrostatics , 198 

I 

Implements required for the farm. . 7 

9,117 

" Construction and use 

of 115 

Improvements in Farm Machinery. 8 

Inclined Plane 63 

Inertia 11 

" apparatus 12 

M Effects of, on wagons 13, 17 

J 

Joint, Universal 60 

K 

Kirby Mower and Reaper 159 

" Reaper, Hand-rake for 160 

" " Self-raking 161 

Knee-joint, or Toggle-joint 71 

Knives in mowers and reapers, 

Form of 158 

Kooloo Plow 118 

I< 

Labor, Application of 108 

" of men and horses 110 

Ladders, Self-supporting 40 

Lapping and flat furrows 127, 128 

Latent heat 273 

" " Advantages of. 275 

Law of virtual velocities 43 

Leveling Instruments 215 

Levers 45 

" of the second kind 45 

" " first kind 46 

• « " third kind 46 

" Calculating power of. — 49,50 

" Examples of. 46 

" Combination of 50 

Line of direction 36 

Liquids, Velocity of, in falling 211 

" Discharge through pipes. .212 

Loads on sideling roads 37 

Lubricating substances 90 



300 



INDEX. 



M 

Machinery iu connection with water.198 

Machines, Advantages of 42 

11 Models of 113 

" Complex, objectionable. .116 
" Construction and use of. .115 
" Required for the Farm. 7, 

9,117 

Marsh's Harvester 163 

Materials, Measuring strength of. .. 29 

Mechanical powers 42 

" principles, Advantages 

of 10 

Mechanical principles, Application 

of 75 

Models of machines 113 

Moline Plow 120 

Momentum 14 

" Calculating quantity of.. 18 

" of railway trains 18 

Moorish Plow 118 

Morgan's Harrow 144 

Motion, Compound 19 

Mouldboard of the Plow, Form of. .124 
Mountains, Height of, measured by 

barometer 243 

Mowing Machine, Wood's 158 

" " Kirby's 159 

" " Buckeye 159 

" " Cayuga Chief.... 160 

Mowing Machines, Construction of.158 

" " How to select... 164 

Myers' Horse-fork 177 

N 

Norwegian Harrow 144 

O 

Ogle, inventor of the Finger-bar.... 159 
Ox-yokes 78 

P 

Packer's Stone Lifter 62 

Palmer's Horse-fork 176 

' ' Hay-stacking Machine 183 

Paradox, Hydrostatic 203 

Pile Engine or Driver 15 

Pinions, Operation of 60 

Pipes, To determine strength of 200 

" Discharge of water through, 
213, 2S4 



Pitts 1 Straw-carrier and Thrasher. . . 190 
Plank roads, Amount of resistance 

on 84,86 

Planting Machines 152 

Plaster Sower, Seymour's 155 

Platform Scales 52, 53 

Plow, Kooloo 118 

" Moorish , 118 

" German 119 

" Modern improved 119 

" Moline Steel ...120 

" Woodruff & Allen's 120 

" Double Michigan 131 

" Mole 139 

" Ditching 138 

" Side-hill or Swivel 132 

" Subsoil 133, 135 

' l Trench 134 

" Paring 137 

" Gang 137 

" Defects in 122 

" Character of a good one 121 

" Cutting edge of. 121 

" Resistance of different parts. .122 

" Form of the mouldboard 124 

" Appendages to 140 

" Wheel coulter and Weed-hook 

on 140 

Plowing, Operation of. 128 

" Fast and slow 130 

" Requisites for success in.. 129 

Potato Planter, True's 156 

" Digger 144 

Power of a horse, Estimating 110 

Press, Hydraulic 205 

Presses for hay 184 

Pressure of liquids, Determining. . . 202 

" Upward, Measuring 199 

" " in liquids 198 

Pulley 61 

Pulverizers 140 

Pump, Cistern : 219 

" Non-freezing 219 

" Drive 220 

" for deep wells 220 

" Chain 221 

11 Rotary 222 

" Suction and Forcing 223 

Pumping water by wind 248 

Pumps, Construction of 218 

Pyramids, Firmness of 38 

Pyrometer, how made 26« 9 



INDEX. 



301 



R 

Rake, Simple form of. 167 

" Revolving 108 

" " Warner's 10!) 

" Spring-tooth 170 

" " " Hollingsworth's.171 

Ram, Hydraulic 226 

Raymond's Hay Elevator 17S 

Reaping Machines during the war. . 8 
Self-rakers for.. 161 

11 " Headers 163 

" " How to select... 161 

Revolving Hay Rake 168 

Roads, importance of good ones.... 6S 

" How to form the bed of 67 

** Measuring the friction on. . . 81 

" Amount of resistance on 86 

" Goodandbad 69 

" Ascent in 63, 66 

" Cost of going up and down 

hill 65 

Rocks, Machines for removing 62 

Rockers, How to make 41 

Rogers 152 

Rolling Mill, Principle of 74 

Root Washer 193 

" Slicers 194 

Rotary Spader, Comstock's 148, 117 

" Pump 222 

S 

Sack-barrow, a lever 48 

Sap, Ascent of. 33 

Scotch or Square Harrow 143 

Screw 70 

" Archimedean 217 

" Estimating power of.. 71 

Seed Sower 153 

" " Harrington's 157 

Self-raking Reapers 161 

Seymour's Broadcast Sower 154 

Shares' Harrow 145 

Side-hill or Swivel Plow 132 

Single-tree, Wier's 98 

Sowing Machines 152 

Specific gravities, how determined. 208 

" " Table of. 209 

Springs of water 201 

Stacks, Building by machinery 182 

Steam engine, Construction of. 265, 267 
" " for farm purposes..,. 270 



Steel Plows... 120 

Steelyard 47 

Stone-lifter 62 

Straw-cutters 16, 75 

" carrier, Pitts' 190 

Strength of materials 29 

" " wood, iron, and ropes. 30 

" " rods and bars 79,80 

" " pipes, To determine... 200 

Stubble Plow, Holbrook's 126 

Stump-puller 54 

Subsoil plowing 133 

" Plows 135 

Swivel Plow 132 

Syphon 244 

" used for draining 243 

T 

Teeth of wheels 58 

Thill-cultivator, Alden's 146 

Thrashing by machinery 187 

" machine, Comparative 

cheapness of. 188 

Thrashing machine, Endless-chain 

power for 188 

Thrashing machine, Pitts' 190 

Toggle-joint power 71 

Tread horse-powers 1S8 

" " " To determine 

work of 188 

Turbine Water-wheel 223 

" " " Reynolds' 224 

" " " Van de Wa- 
ter's 224 

U 

Universal joint 60 

Upward pressure of liquids 198 

V 

Vacuum, Machine running in 11 

Velocity affects friction but slightly. 88 

" of falling water 211 

" of water in ditches .... 214, 286 

" " through pipes 284 

Ventilation 257 

" through walls and gar- 
rets 258 

Ventilator, Griffith's 258 

" Emerson's 255 

Virtual velocities, Law or rule of. . . 43 



302 



INDEX. 



W 

Wagon springs, Advantages of 17 

" wheels, Proper width for. . .-. 87 

Warner's Revolving Rake 169 

Washing Machine 72 

Water, Remarkable effects of heat 

on 279 

Water, Velocity of 211, 213 

" Discharge of, through pipes. 212 

" in ditches .„ 214 

" wheels, Turbine. 223 

" ram 226 

" engines 230 

Waves, Nature of. 232 

" Velocity of 234 

" Breadth and height of 233 

4 ' To prevent inroads of . . 235, 236 

Weather glass 243 

Wedge 69 

Weed hook on plows 140 



Weighing machine, or platform 

scales. 52, 53 

Wheat drill 152 

" " Bickford & Huffman's, 

Construction of 153 

Wheel and axle. . 55 

" " " Modifications of ... . 57 

Wheelbarrow, Operation of 47 

Wheel-cutter to plows 140 

Wheels, large ones run best 39 

" for wagons Proper width 

for 87 

Whiffle-tree? for three horses 50, 97 

Wind, Causes of 252 

" Velocity of. . . . 246 

" mill 247 

" " Pumping water by 248 

" "Brown's 251 

Wooden legs, why hard to walk on. 40 

Wood's Plow 119 

Work of men and horses, Estima- 
ting 110 



3477 



